diff --git a/config/config.md b/config/config.md
index 0fae0caaa4..aa0c6701a0 100644
--- a/config/config.md
+++ b/config/config.md
@@ -14,6 +14,7 @@
 | --- | -----| ------- | ----------- |
 | `default_timezone` | String | Unset | The default timezone of the server. |
 | `default_column_prefix` | String | Unset | The default column prefix for auto-created time index and value columns. |
+| `auto_create_table` | Bool | `true` | Server-side global switch for auto table creation on write.<br/>When `false`, a missing table is never auto-created even if the request sets the `auto_create_table` hint to `true`. Default: `true`. |
 | `user_provider` | String | Unset | The user provider for authentication.<br/>Examples: "static_user_provider:file:/path/to/users", "static_user_provider:cmd:greptime_user=greptime_pwd" |
 | `max_in_flight_write_bytes` | String | Unset | Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `write_bytes_exhausted_policy` | String | Unset | Policy when write bytes quota is exhausted.<br/>Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail" |
@@ -230,6 +231,7 @@
 | --- | -----| ------- | ----------- |
 | `default_timezone` | String | Unset | The default timezone of the server. |
 | `default_column_prefix` | String | Unset | The default column prefix for auto-created time index and value columns. |
+| `auto_create_table` | Bool | `true` | Server-side global switch for auto table creation on write.<br/>When `false`, a missing table is never auto-created even if the request sets the `auto_create_table` hint to `true`. Default: `true`. |
 | `user_provider` | String | Unset | The user provider for authentication.<br/>Examples: "static_user_provider:file:/path/to/users", "static_user_provider:cmd:greptime_user=greptime_pwd" |
 | `max_in_flight_write_bytes` | String | Unset | Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `write_bytes_exhausted_policy` | String | Unset | Policy when write bytes quota is exhausted.<br/>Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail" |
diff --git a/config/frontend.example.toml b/config/frontend.example.toml
index 39f38fbef9..a044aebda6 100644
--- a/config/frontend.example.toml
+++ b/config/frontend.example.toml
@@ -6,6 +6,10 @@ default_timezone = "UTC"
 ## @toml2docs:none-default
 default_column_prefix = "greptime"
 
+## Server-side global switch for auto table creation on write.
+## When `false`, a missing table is never auto-created even if the request sets the `auto_create_table` hint to `true`. Default: `true`.
+#+ auto_create_table = true
+
 ## The user provider for authentication.
 ## Examples: "static_user_provider:file:/path/to/users", "static_user_provider:cmd:greptime_user=greptime_pwd"
 ## @toml2docs:none-default
diff --git a/config/standalone.example.toml b/config/standalone.example.toml
index d5c42e744c..5740e0e1cf 100644
--- a/config/standalone.example.toml
+++ b/config/standalone.example.toml
@@ -6,6 +6,10 @@ default_timezone = "UTC"
 ## @toml2docs:none-default
 default_column_prefix = "greptime"
 
+## Server-side global switch for auto table creation on write.
+## When `false`, a missing table is never auto-created even if the request sets the `auto_create_table` hint to `true`. Default: `true`.
+#+ auto_create_table = true
+
 ## The user provider for authentication.
 ## Examples: "static_user_provider:file:/path/to/users", "static_user_provider:cmd:greptime_user=greptime_pwd"
 ## @toml2docs:none-default
diff --git a/src/cmd/tests/load_config_test.rs b/src/cmd/tests/load_config_test.rs
index 6cffcd67c2..cee29e4456 100644
--- a/src/cmd/tests/load_config_test.rs
+++ b/src/cmd/tests/load_config_test.rs
@@ -114,6 +114,7 @@ fn test_load_frontend_example_config() {
         component: FrontendOptions {
             default_timezone: Some("UTC".to_string()),
             default_column_prefix: Some("greptime".to_string()),
+            auto_create_table: true,
             meta_client: Some(MetaClientOptions {
                 metasrv_addrs: vec!["127.0.0.1:3002".to_string()],
                 timeout: Duration::from_secs(3),
@@ -267,6 +268,7 @@ fn test_load_standalone_example_config() {
         component: StandaloneOptions {
             default_timezone: Some("UTC".to_string()),
             default_column_prefix: Some("greptime".to_string()),
+            auto_create_table: true,
             wal: DatanodeWalConfig::RaftEngine(RaftEngineConfig {
                 dir: Some(format!("{}/{}", DEFAULT_DATA_HOME, WAL_DIR)),
                 sync_period: Some(Duration::from_secs(10)),
diff --git a/src/flow/src/server.rs b/src/flow/src/server.rs
index 913128f386..c2d986f645 100644
--- a/src/flow/src/server.rs
+++ b/src/flow/src/server.rs
@@ -566,11 +566,15 @@ impl FrontendInvoker {
                 name: TABLE_FLOWNODE_SET_CACHE_NAME,
             })?;
 
+        // TODO(auto_create_table): flow sink tables are created through a controlled
+        // `CREATE FLOW` path, not client writes, so they are intentionally exempt from
+        // the frontend's global auto-create switch. Revisit if flow should honor it.
         let inserter = Arc::new(Inserter::new(
             catalog_manager.clone(),
             partition_manager.clone(),
             node_manager.clone(),
             table_flownode_cache,
+            true,
         ));
 
         let deleter = Arc::new(Deleter::new(
diff --git a/src/frontend/src/frontend.rs b/src/frontend/src/frontend.rs
index fb3b096f06..918185cb8f 100644
--- a/src/frontend/src/frontend.rs
+++ b/src/frontend/src/frontend.rs
@@ -44,6 +44,11 @@ pub struct FrontendOptions {
     pub node_id: Option<String>,
     pub default_timezone: Option<String>,
     pub default_column_prefix: Option<String>,
+    /// Server-side global switch for auto table creation on write.
+    /// Acts as an upper bound: when `false`, missing tables are never auto-created
+    /// even if a request sets the `auto_create_table` hint to `true`. When `true`
+    /// (default), the per-request hint still applies. Default: `true`.
+    pub auto_create_table: bool,
     /// Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).
     /// Set to 0 to disable the limit. Default: "0" (unlimited)
     pub max_in_flight_write_bytes: ReadableSize,
@@ -82,6 +87,7 @@ impl Default for FrontendOptions {
             node_id: None,
             default_timezone: None,
             default_column_prefix: None,
+            auto_create_table: true,
             max_in_flight_write_bytes: ReadableSize(0),
             write_bytes_exhausted_policy: OnExhaustedPolicy::default(),
             http: HttpOptions::default(),
diff --git a/src/frontend/src/instance/builder.rs b/src/frontend/src/instance/builder.rs
index ff857ed768..526d8aac73 100644
--- a/src/frontend/src/instance/builder.rs
+++ b/src/frontend/src/instance/builder.rs
@@ -185,6 +185,7 @@ impl FrontendBuilder {
             partition_manager.clone(),
             node_manager.clone(),
             table_flownode_cache,
+            self.options.auto_create_table,
         ));
         let deleter = Arc::new(Deleter::new(
             self.catalog_manager.clone(),
diff --git a/src/operator/src/insert.rs b/src/operator/src/insert.rs
index ff8ed2b78b..9ef4d2ff94 100644
--- a/src/operator/src/insert.rs
+++ b/src/operator/src/insert.rs
@@ -83,6 +83,10 @@ pub struct Inserter {
     pub(crate) partition_manager: PartitionRuleManagerRef,
     pub(crate) node_manager: NodeManagerRef,
     pub(crate) table_flownode_set_cache: TableFlownodeSetCacheRef,
+    /// Server-side upper bound for auto table creation on write.
+    /// When `false`, missing tables are never auto-created regardless of the
+    /// per-request `auto_create_table` hint. When `true`, the hint still applies.
+    auto_create_table: bool,
 }
 
 pub type InserterRef = Arc<Inserter>;
@@ -135,12 +139,14 @@ impl Inserter {
         partition_manager: PartitionRuleManagerRef,
         node_manager: NodeManagerRef,
         table_flownode_set_cache: TableFlownodeSetCacheRef,
+        auto_create_table: bool,
     ) -> Self {
         Self {
             catalog_manager,
             partition_manager,
             node_manager,
             table_flownode_set_cache,
+            auto_create_table,
         }
     }
 
@@ -469,6 +475,30 @@ impl Inserter {
         Ok(inserts)
     }
 
+    /// Returns `None` if auto table creation is allowed, or `Some(reason)` if
+    /// disabled by either the global config or the request hint. The reason tells
+    /// which one, for a clearer error.
+    fn auto_create_disabled_reason(&self, ctx: &QueryContextRef) -> Result<Option<&'static str>> {
+        let auto_create_table_hint = ctx
+            .extension(AUTO_CREATE_TABLE_KEY)
+            .map(|v| v.parse::<bool>())
+            .transpose()
+            .map_err(|_| {
+                InvalidInsertRequestSnafu {
+                    reason: "`auto_create_table` hint must be a boolean",
+                }
+                .build()
+            })?
+            .unwrap_or(true);
+        Ok(if !self.auto_create_table {
+            Some("auto-create table is disabled by frontend config")
+        } else if !auto_create_table_hint {
+            Some("`auto_create_table` hint is disabled")
+        } else {
+            None
+        })
+    }
+
     /// Creates or alter tables on demand:
     /// - if table does not exist, create table by inferred CreateExpr
     /// - if table exist, check if schema matches. If any new column found, alter table by inferred `AlterExpr`
@@ -498,19 +528,7 @@ impl Inserter {
         let schema = ctx.current_schema();
 
         let mut table_infos = HashMap::new();
-        // If `auto_create_table` hint is disabled, skip creating/altering tables.
-        let auto_create_table_hint = ctx
-            .extension(AUTO_CREATE_TABLE_KEY)
-            .map(|v| v.parse::<bool>())
-            .transpose()
-            .map_err(|_| {
-                InvalidInsertRequestSnafu {
-                    reason: "`auto_create_table` hint must be a boolean",
-                }
-                .build()
-            })?
-            .unwrap_or(true);
-        if !auto_create_table_hint {
+        if let Some(disabled_reason) = self.auto_create_disabled_reason(ctx)? {
             let mut instant_table_ids = HashSet::new();
             for req in &requests.inserts {
                 let table = self
@@ -518,8 +536,8 @@ impl Inserter {
                     .await?
                     .context(InvalidInsertRequestSnafu {
                         reason: format!(
-                            "Table `{}` does not exist, and `auto_create_table` hint is disabled",
-                            req.table_name
+                            "Table `{}` does not exist, and {}",
+                            req.table_name, disabled_reason
                         ),
                     })?;
                 let table_info = table.table_info();
@@ -767,6 +785,16 @@ impl Inserter {
             return Ok(());
         }
 
+        // Gate here too, otherwise a disabled switch would still leak the physical table.
+        if let Some(disabled_reason) = self.auto_create_disabled_reason(ctx)? {
+            return InvalidInsertRequestSnafu {
+                reason: format!(
+                    "Physical table `{physical_table}` does not exist, and {disabled_reason}"
+                ),
+            }
+            .fail();
+        }
+
         let table_reference = TableReference::full(catalog_name, &schema_name, &physical_table);
         info!("Physical metric table `{table_reference}` does not exist, try creating table");
 
@@ -1333,6 +1361,7 @@ mod tests {
                 Cache::new(100),
                 kv_backend.clone(),
             )),
+            true,
         );
         let alter_expr = inserter
             .get_alter_table_expr_on_demand(&mut req, &table, &ctx, true, true)
diff --git a/src/standalone/src/options.rs b/src/standalone/src/options.rs
index dece6389f0..bf1000fd58 100644
--- a/src/standalone/src/options.rs
+++ b/src/standalone/src/options.rs
@@ -38,6 +38,10 @@ pub struct StandaloneOptions {
     pub enable_telemetry: bool,
     pub default_timezone: Option<String>,
     pub default_column_prefix: Option<String>,
+    /// Server-side global switch for auto table creation on write.
+    /// Upper bound: when `false`, missing tables are never auto-created even if a
+    /// request sets the `auto_create_table` hint to `true`. Default: `true`.
+    pub auto_create_table: bool,
     /// Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).
     /// Set to 0 to disable the limit. Default: "0" (unlimited)
     pub max_in_flight_write_bytes: ReadableSize,
@@ -77,6 +81,7 @@ impl Default for StandaloneOptions {
             enable_telemetry: true,
             default_timezone: None,
             default_column_prefix: None,
+            auto_create_table: true,
             max_in_flight_write_bytes: ReadableSize(0),
             write_bytes_exhausted_policy: OnExhaustedPolicy::default(),
             http: HttpOptions::default(),
@@ -130,6 +135,7 @@ impl StandaloneOptions {
         let cloned_opts = self.clone();
         FrontendOptions {
             default_timezone: cloned_opts.default_timezone,
+            auto_create_table: cloned_opts.auto_create_table,
             max_in_flight_write_bytes: cloned_opts.max_in_flight_write_bytes,
             write_bytes_exhausted_policy: cloned_opts.write_bytes_exhausted_policy,
             http: cloned_opts.http,
diff --git a/tests-integration/src/standalone.rs b/tests-integration/src/standalone.rs
index b013b8b0d4..74a1501207 100644
--- a/tests-integration/src/standalone.rs
+++ b/tests-integration/src/standalone.rs
@@ -80,6 +80,7 @@ pub struct GreptimeDbStandaloneBuilder {
     default_store: Option<StorageType>,
     plugin: Option<Plugins>,
     slow_query_options: SlowQueryOptions,
+    auto_create_table: bool,
 }
 
 impl GreptimeDbStandaloneBuilder {
@@ -97,9 +98,16 @@ impl GreptimeDbStandaloneBuilder {
                 threshold: Duration::from_secs(1),
                 ..Default::default()
             },
+            auto_create_table: true,
         }
     }
 
+    #[must_use]
+    pub fn with_auto_create_table(mut self, auto_create_table: bool) -> Self {
+        self.auto_create_table = auto_create_table;
+        self
+    }
+
     #[must_use]
     pub fn with_default_store_type(self, store_type: StorageType) -> Self {
         Self {
@@ -347,6 +355,7 @@ impl GreptimeDbStandaloneBuilder {
             wal: self.metasrv_wal_config.clone().into(),
             grpc: GrpcOptions::default().with_server_addr("127.0.0.1:4001"),
             slow_query: self.slow_query_options.clone(),
+            auto_create_table: self.auto_create_table,
             ..StandaloneOptions::default()
         };
 
diff --git a/tests-integration/src/test_util.rs b/tests-integration/src/test_util.rs
index 15d65c34ea..60e0d9143e 100644
--- a/tests-integration/src/test_util.rs
+++ b/tests-integration/src/test_util.rs
@@ -649,6 +649,20 @@ pub async fn setup_grpc_server_with_user_provider(
     setup_grpc_server_with(store_type, name, user_provider, None, None).await
 }
 
+/// Sets up a gRPC server backed by a standalone instance whose frontend has auto
+/// table creation disabled, for testing the server-side global switch.
+pub async fn setup_grpc_server_with_auto_create_table_disabled(
+    store_type: StorageType,
+    name: &str,
+) -> (GreptimeDbStandalone, Arc<GrpcServer>) {
+    let instance = GreptimeDbStandaloneBuilder::new(name)
+        .with_default_store_type(store_type)
+        .with_auto_create_table(false)
+        .build()
+        .await;
+    setup_grpc_server_for_instance(instance, None, None, None).await
+}
+
 pub async fn setup_grpc_server_with(
     store_type: StorageType,
     name: &str,
@@ -657,7 +671,17 @@ pub async fn setup_grpc_server_with(
     memory_limiter: Option<servers::request_memory_limiter::ServerMemoryLimiter>,
 ) -> (GreptimeDbStandalone, Arc<GrpcServer>) {
     let instance = setup_standalone_instance(name, store_type).await;
+    setup_grpc_server_for_instance(instance, user_provider, grpc_config, memory_limiter).await
+}
 
+/// Builds and starts a gRPC server on top of an already-constructed standalone
+/// instance. This is the shared core behind the `setup_grpc_server_*` helpers.
+async fn setup_grpc_server_for_instance(
+    instance: GreptimeDbStandalone,
+    user_provider: Option<UserProviderRef>,
+    grpc_config: Option<GrpcServerConfig>,
+    memory_limiter: Option<servers::request_memory_limiter::ServerMemoryLimiter>,
+) -> (GreptimeDbStandalone, Arc<GrpcServer>) {
     let runtime: Runtime = RuntimeBuilder::default()
         .worker_threads(2)
         .thread_name("grpc-handlers")
diff --git a/tests-integration/tests/grpc.rs b/tests-integration/tests/grpc.rs
index 0f1112ff4a..d6b96484af 100644
--- a/tests-integration/tests/grpc.rs
+++ b/tests-integration/tests/grpc.rs
@@ -44,7 +44,8 @@ use servers::request_memory_limiter::ServerMemoryLimiter;
 use servers::server::Server;
 use servers::tls::{TlsMode, TlsOption};
 use tests_integration::test_util::{
-    StorageType, setup_grpc_server, setup_grpc_server_with, setup_grpc_server_with_user_provider,
+    StorageType, setup_grpc_server, setup_grpc_server_with,
+    setup_grpc_server_with_auto_create_table_disabled, setup_grpc_server_with_user_provider,
 };
 use tonic::Request;
 use tonic::metadata::MetadataValue;
@@ -82,6 +83,7 @@ macro_rules! grpc_tests {
                 test_invalid_dbname,
                 test_auto_create_table,
                 test_auto_create_table_with_hints,
+                test_auto_create_table_disabled_by_config,
                 test_otel_arrow_auth,
                 test_insert_and_select,
                 test_dbname,
@@ -405,6 +407,81 @@ pub async fn test_auto_create_table_with_hints(store_type: StorageType) {
     let _ = fe_grpc_server.shutdown().await;
 }
 
+/// When the frontend global switch disables auto table creation, a write to a
+/// missing table must fail even if the request sets `auto_create_table=true`,
+/// proving the global config is an upper bound that hints cannot bypass.
+pub async fn test_auto_create_table_disabled_by_config(store_type: StorageType) {
+    let (_db, fe_grpc_server) = setup_grpc_server_with_auto_create_table_disabled(
+        store_type,
+        "test_auto_create_table_disabled_by_config",
+    )
+    .await;
+    let addr = fe_grpc_server.bind_addr().unwrap().to_string();
+
+    let grpc_client = Client::with_urls(vec![addr]);
+    let db = Database::new(DEFAULT_CATALOG_NAME, DEFAULT_SCHEMA_NAME, grpc_client);
+
+    // Plain row insert to a missing table: must fail even with `auto_create_table=true`.
+    let (host, cpu, mem, ts) = expect_data();
+    let request = InsertRequest {
+        table_name: "demo".to_string(),
+        columns: vec![host, cpu, mem, ts],
+        row_count: 4,
+    };
+    let result = db
+        .insert_with_hints(
+            InsertRequests {
+                inserts: vec![request],
+            },
+            &[("auto_create_table", "true")],
+        )
+        .await;
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("does not exist") && err.contains("disabled by frontend config"),
+        "unexpected error: {err}"
+    );
+
+    // Metric path (via `physical_table` hint): must also fail without leaking the physical table.
+    let (host, cpu, mem, ts) = expect_data();
+    let request = InsertRequest {
+        table_name: "demo_metric".to_string(),
+        columns: vec![host, cpu, mem, ts],
+        row_count: 4,
+    };
+    let result = db
+        .insert_with_hints(
+            InsertRequests {
+                inserts: vec![request],
+            },
+            &[
+                ("auto_create_table", "true"),
+                ("physical_table", "greptime_physical_table"),
+            ],
+        )
+        .await;
+    let err = result.unwrap_err().to_string();
+    assert!(
+        err.contains("does not exist") && err.contains("disabled by frontend config"),
+        "unexpected error: {err}"
+    );
+
+    // The physical table must not have been created before the failure.
+    let output = db.sql("SHOW TABLES").await.unwrap();
+    let record_batches = match output.data {
+        OutputData::RecordBatches(record_batches) => record_batches,
+        OutputData::Stream(stream) => RecordBatches::try_collect(stream).await.unwrap(),
+        OutputData::AffectedRows(_) => unreachable!(),
+    };
+    let tables = record_batches.pretty_print().unwrap();
+    assert!(
+        !tables.contains("greptime_physical_table"),
+        "physical table leaked despite disabled auto-create:\n{tables}"
+    );
+
+    let _ = fe_grpc_server.shutdown().await;
+}
+
 fn expect_data() -> (Column, Column, Column, Column) {
     // testing data:
     let expected_host_col = Column {
diff --git a/tests-integration/tests/http.rs b/tests-integration/tests/http.rs
index 7f411cdec2..6e35ed7656 100644
--- a/tests-integration/tests/http.rs
+++ b/tests-integration/tests/http.rs
@@ -1491,6 +1491,7 @@ mem_threshold_on_create = "auto"
     let expected_toml_str = format!(
         r#"
 enable_telemetry = true
+auto_create_table = true
 max_in_flight_write_bytes = "0KiB"
 write_bytes_exhausted_policy = "wait"
 init_regions_in_background = false