diff --git a/components/calendar/__tests__/calendar-app.test.tsx b/components/calendar/__tests__/calendar-app.test.tsx
index bb1fce2ce..b3cf8dfeb 100644
--- a/components/calendar/__tests__/calendar-app.test.tsx
+++ b/components/calendar/__tests__/calendar-app.test.tsx
@@ -591,3 +591,12 @@ describe('CalendarApp view menu', () => {
     expect(useCalendarStore.getState().viewMode).toBe('day');
   });
 });
+
+describe('CalendarApp long names', () => {
+  it('shows the full name of a cut-off calendar on hover', () => {
+    const long = { ...calendars[0], name: 'Stalwart Calendar (usera@internal.bulwarkmail.org)' };
+    useCalendarStore.setState({ calendars: [long] } as never);
+    renderApp();
+    expect(screen.getByTestId('calendar-item').querySelector('[title]')).toHaveAttribute('title', long.name);
+  });
+});
diff --git a/components/calendar/calendar-agenda-view.tsx b/components/calendar/calendar-agenda-view.tsx
index b24857449..19cbb7383 100644
--- a/components/calendar/calendar-agenda-view.tsx
+++ b/components/calendar/calendar-agenda-view.tsx
@@ -264,13 +264,13 @@ export function CalendarAgendaView({
                   />
 
                   <div className="flex-1 min-w-0">
-                    <div className={cn("text-sm font-medium truncate", isInactive && "line-through text-muted-foreground")}>
+                    <div className={cn("text-sm font-medium truncate", isInactive && "line-through text-muted-foreground")} title={ev.title || t("events.no_title")}>
                       {ev.title || t("events.no_title")}
                     </div>
                     {(meta || getParticipantCount(ev) > 0) && (
                       <div className="flex items-center gap-2 text-xs text-muted-foreground mt-0.5 min-w-0">
                         {locationName && <MapPin className="w-3 h-3 flex-shrink-0" />}
-                        {meta && <span className="truncate">{meta}</span>}
+                        {meta && <span className="truncate" title={meta}>{meta}</span>}
                         {getParticipantCount(ev) > 0 && (
                           <span className="flex items-center gap-1 flex-shrink-0">
                             <Users className="w-3 h-3" />
diff --git a/components/calendar/calendar-day-view.tsx b/components/calendar/calendar-day-view.tsx
index bfbea0869..bc10e3983 100644
--- a/components/calendar/calendar-day-view.tsx
+++ b/components/calendar/calendar-day-view.tsx
@@ -415,7 +415,7 @@ export function CalendarDayView({
                                   >
                                     {isCompleted && <Check className="h-2.5 w-2.5" />}
                                   </button>
-                                  <span className={cn("truncate", isCompleted && "line-through text-muted-foreground")}>
+                                  <span className={cn("truncate", isCompleted && "line-through text-muted-foreground")} title={task.title || t("tasks.no_title")}>
                                     {task.title || t("tasks.no_title")}
                                   </span>
                                 </div>
diff --git a/components/calendar/calendar-sidebar-panel.tsx b/components/calendar/calendar-sidebar-panel.tsx
index b837980c2..a9f99e201 100644
--- a/components/calendar/calendar-sidebar-panel.tsx
+++ b/components/calendar/calendar-sidebar-panel.tsx
@@ -315,7 +315,7 @@ export function CalendarSidebarPanel({
           >
             {isVisible && <Check className="w-2.5 h-2.5" stroke={3.5} />}
           </span>
-          <span className={cn("truncate", !isVisible && "text-muted-foreground")}>
+          <span className={cn("truncate", !isVisible && "text-muted-foreground")} title={cal.name}>
             {cal.name}
           </span>
           {isSubscriptionCalendar(cal.id) && (
@@ -483,7 +483,7 @@ export function CalendarSidebarPanel({
           ) : (
             <ChevronRight className="w-3 h-3 text-muted-foreground flex-shrink-0" />
           )}
-          <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider truncate">{label}</span>
+          <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider truncate" title={label}>{label}</span>
         </button>
         {onAdd && (
           <IconButton
@@ -545,7 +545,7 @@ export function CalendarSidebarPanel({
                     <ChevronRight className="w-3.5 h-3.5 text-muted-foreground flex-shrink-0" />
                   )}
                   <User className="w-3.5 h-3.5 text-muted-foreground flex-shrink-0" />
-                  <span className="text-xs font-semibold text-foreground/90 truncate">
+                  <span className="text-xs font-semibold text-foreground/90 truncate" title={group.label}>
                     {group.label}
                   </span>
                   {isActive && onCreateCalendar && (
diff --git a/components/calendar/calendar-toolbar.tsx b/components/calendar/calendar-toolbar.tsx
index 543c938e9..aab0d46c1 100644
--- a/components/calendar/calendar-toolbar.tsx
+++ b/components/calendar/calendar-toolbar.tsx
@@ -212,7 +212,7 @@ export function CalendarToolbar({
                   <ChevronLeft />
                 </IconButton>
               )}
-              <span className="text-sm font-semibold text-center flex-1 select-none truncate">
+              <span className="text-sm font-semibold text-center flex-1 select-none truncate" title={getDateLabel()}>
                 {getDateLabel()}
               </span>
               {hasDateNav && (
@@ -284,7 +284,7 @@ export function CalendarToolbar({
                                 )}
                                 style={isVisible ? { backgroundColor: color, borderColor: color } : undefined}
                               />
-                              <span className={cn("truncate", !isVisible && "text-muted-foreground")}>
+                              <span className={cn("truncate", !isVisible && "text-muted-foreground")} title={cal.name}>
                                 {cal.name}
                               </span>
                             </button>
@@ -324,7 +324,7 @@ export function CalendarToolbar({
                                       )}
                                       style={isVisible ? { backgroundColor: color, borderColor: color } : undefined}
                                     />
-                                    <span className={cn("truncate", !isVisible && "text-muted-foreground")}>
+                                    <span className={cn("truncate", !isVisible && "text-muted-foreground")} title={cal.name}>
                                       {cal.name}
                                     </span>
                                   </button>
@@ -406,7 +406,7 @@ export function CalendarToolbar({
           </Button>
         </>
       )}
-      <h1 className="ms-2 text-base font-semibold truncate select-none">
+      <h1 className="ms-2 text-base font-semibold truncate select-none" title={getDateLabel()}>
         {getDateLabel()}
       </h1>
 
diff --git a/components/calendar/event-detail-popover.tsx b/components/calendar/event-detail-popover.tsx
index cec55f9c6..e2dcce031 100644
--- a/components/calendar/event-detail-popover.tsx
+++ b/components/calendar/event-detail-popover.tsx
@@ -541,7 +541,7 @@ export function EventDetailPopover({
               <div className="mt-1 space-y-0.5">
                 {participants.slice(0, 5).map((p) => (
                   <div key={p.id} className="flex items-center justify-between gap-2 text-xs">
-                    <span className="truncate text-foreground">
+                    <span className="truncate text-foreground" title={p.email}>
                       {p.name || p.email}
                       {p.isOrganizer && (
                         <span className="text-muted-foreground ms-1">
@@ -582,7 +582,7 @@ export function EventDetailPopover({
         {calendar && (
           <div className="flex items-start gap-2.5">
             <CalendarIcon className="w-4 h-4 text-muted-foreground mt-0.5 flex-shrink-0" />
-            <span className="text-sm text-foreground truncate">{calendar.name}</span>
+            <span className="text-sm text-foreground truncate" title={calendar.name}>{calendar.name}</span>
           </div>
         )}
 
diff --git a/components/calendar/event-modal.tsx b/components/calendar/event-modal.tsx
index 5ce9119a3..fadf52a38 100644
--- a/components/calendar/event-modal.tsx
+++ b/components/calendar/event-modal.tsx
@@ -967,7 +967,7 @@ export function EventModal({
     return (
       <div ref={modalRef} role="dialog" aria-modal={isMobile || undefined} aria-label={event.title || t("events.no_title")} className={isMobile ? mobileRootClass : "flex flex-col h-full bg-background"}>
         <div className="flex items-center justify-between gap-2 px-6 py-4 border-b border-border flex-shrink-0">
-          <h2 className="text-lg font-semibold truncate">{event.title || t("events.no_title")}</h2>
+          <h2 className="text-lg font-semibold truncate" title={event.title || t("events.no_title")}>{event.title || t("events.no_title")}</h2>
           {onMore && (
             <IconButton label={t("toolbar.more")} aria-haspopup="menu" className="ms-auto flex-shrink-0" onClick={(e) => onMore(e.currentTarget)}>
               <MoreVertical />
@@ -1048,7 +1048,7 @@ export function EventModal({
                 <div className="space-y-1 ps-5">
                   {participants.map(p => (
                     <div key={p.id} className="flex items-center justify-between text-sm">
-                      <span className="truncate">
+                      <span className="truncate" title={p.email}>
                         {p.name || p.email}
                         {p.isOrganizer && (
                           <span className="text-muted-foreground ms-1">({t("participants.organizer").toLowerCase()})</span>
@@ -1095,7 +1095,7 @@ export function EventModal({
           <div className="min-w-0 flex-1">
             <div className="flex items-center gap-2">
               <span className="w-2.5 h-2.5 rounded-full flex-shrink-0" style={{ backgroundColor: color }} />
-              <h2 className="text-lg font-semibold truncate">{event.title || t("events.no_title")}</h2>
+              <h2 className="text-lg font-semibold truncate" title={event.title || t("events.no_title")}>{event.title || t("events.no_title")}</h2>
             </div>
             {eventCalendar && (
               <p className="text-xs text-muted-foreground mt-0.5 ps-[18px]">{eventCalendar.name}</p>
@@ -1205,7 +1205,7 @@ export function EventModal({
                   <div className="mt-1 space-y-0.5">
                     {viewParticipants.map((p) => (
                       <div key={p.id} className="flex items-center justify-between gap-2 text-xs">
-                        <span className="truncate text-foreground">
+                        <span className="truncate text-foreground" title={p.email}>
                           {p.name || p.email}
                           {p.isOrganizer && (
                             <span className="text-muted-foreground ms-1">({t("participants.organizer").toLowerCase()})</span>
diff --git a/components/calendar/ical-import-modal.tsx b/components/calendar/ical-import-modal.tsx
index 8389278ca..29967fc5f 100644
--- a/components/calendar/ical-import-modal.tsx
+++ b/components/calendar/ical-import-modal.tsx
@@ -380,7 +380,7 @@ export function ICalImportModal({ calendars, client, onClose, initialUrl }: ICal
                       className="mt-0.5 rounded border-input"
                     />
                     <div className="flex-1 min-w-0">
-                      <p className="text-sm font-medium truncate">
+                      <p className="text-sm font-medium truncate" title={event.title || tCal("events.no_title")}>
                         {event.title || tCal("events.no_title")}
                       </p>
                       <div className="flex items-center gap-2 mt-0.5">
diff --git a/components/calendar/participant-availability.tsx b/components/calendar/participant-availability.tsx
index fa1def251..afde5753c 100644
--- a/components/calendar/participant-availability.tsx
+++ b/components/calendar/participant-availability.tsx
@@ -188,7 +188,7 @@ export function ParticipantAvailability({ attendees, start, end }: ParticipantAv
               )}
               aria-hidden="true"
             />
-            <span className="min-w-0 truncate text-foreground/90">{a.name || a.email}</span>
+            <span className="min-w-0 truncate text-foreground/90" title={a.email}>{a.name || a.email}</span>
             <span className="ms-auto flex shrink-0 items-center gap-1 text-muted-foreground">
               {status === "checking" && <Loader2 className="h-3 w-3 animate-spin" />}
               {t(status)}
diff --git a/components/calendar/participant-input.tsx b/components/calendar/participant-input.tsx
index f615863ae..f4eabc21d 100644
--- a/components/calendar/participant-input.tsx
+++ b/components/calendar/participant-input.tsx
@@ -182,9 +182,9 @@ export const ParticipantInput = forwardRef<ParticipantInputHandle, ParticipantIn
               >
                 <Avatar name={s.name} email={s.email} size="sm" className="shrink-0 w-7 h-7 text-[10px]" />
                 <div className="min-w-0">
-                  <div className="font-medium truncate">{s.name || s.email}</div>
+                  <div className="font-medium truncate" title={s.name || s.email}>{s.name || s.email}</div>
                   {s.name && (
-                    <div className="text-xs text-muted-foreground truncate">{s.email}</div>
+                    <div className="text-xs text-muted-foreground truncate" title={s.email}>{s.email}</div>
                   )}
                 </div>
               </li>
@@ -211,11 +211,12 @@ export const ParticipantInput = forwardRef<ParticipantInputHandle, ParticipantIn
                   }}
                   className="truncate hover:underline focus:outline-none focus:underline cursor-text"
                   aria-label={`${t("edit")} ${p.name || p.email}`}
+                  title={p.email}
                 >
                   {p.name || p.email}
                 </button>
               ) : (
-                <span className="truncate">{p.name || p.email}</span>
+                <span className="truncate" title={p.email}>{p.name || p.email}</span>
               )}
               {!disabled && (
                 <button
diff --git a/components/calendar/task-list-view.tsx b/components/calendar/task-list-view.tsx
index bde0d1232..2ddf2ecf7 100644
--- a/components/calendar/task-list-view.tsx
+++ b/components/calendar/task-list-view.tsx
@@ -234,7 +234,7 @@ export function TaskListView({
                   <span className={cn(
                     "text-sm font-medium truncate",
                     isCompleted && "line-through text-muted-foreground"
-                  )}>
+                  )} title={task.title || t("tasks.no_title")}>
                     {task.title || t("tasks.no_title")}
                   </span>
                   {priorityIcon}