diff --git a/.changeset/timeinput-typed-invalid.md b/.changeset/timeinput-typed-invalid.md
new file mode 100644
index 000000000000..70ba22b4cde1
--- /dev/null
+++ b/.changeset/timeinput-typed-invalid.md
@@ -0,0 +1,6 @@
+---
+'@astryxdesign/core': patch
+---
+
+[fix] TimeInput: typed-invalid input (e.g. an out-of-range time that will be reverted on blur) now sets `aria-invalid` and announces "Invalid time" via an assertive live region, matching DateInput, NumberInput, and DateTimeInput. Previously only the visual red border signalled the invalid state. (#3718)
+@bhamodi
diff --git a/packages/core/src/TimeInput/TimeInput.test.tsx b/packages/core/src/TimeInput/TimeInput.test.tsx
index 61f1b8baed59..e6c0d7e9c9e3 100644
--- a/packages/core/src/TimeInput/TimeInput.test.tsx
+++ b/packages/core/src/TimeInput/TimeInput.test.tsx
@@ -160,6 +160,43 @@ describe('TimeInput', () => {
     expect(onChange).not.toHaveBeenCalled();
   });
 
+  it('sets aria-invalid="true" when typed input is out of range', () => {
+    render(<TimeInput label="Time" onChange={() => {}} />);
+
+    const input = screen.getByRole('textbox');
+    fireEvent.change(input, {target: {value: '25:99'}});
+
+    expect(input).toHaveAttribute('aria-invalid', 'true');
+  });
+
+  it('does not set aria-invalid when typed input is a valid time', () => {
+    render(<TimeInput label="Time" onChange={() => {}} />);
+
+    const input = screen.getByRole('textbox');
+    fireEvent.change(input, {target: {value: '3:45 pm'}});
+
+    expect(input).not.toHaveAttribute('aria-invalid');
+  });
+
+  it('announces an alert message when typed input is invalid', () => {
+    render(<TimeInput label="Time" onChange={() => {}} />);
+
+    const input = screen.getByRole('textbox');
+    fireEvent.change(input, {target: {value: '25:99'}});
+
+    expect(screen.getByRole('alert')).toHaveTextContent('Invalid time');
+  });
+
+  it('does not announce an alert message when input is valid', () => {
+    render(<TimeInput label="Time" onChange={() => {}} />);
+
+    const input = screen.getByRole('textbox');
+    fireEvent.change(input, {target: {value: '3:45 pm'}});
+
+    expect(screen.getByRole('alert')).toHaveTextContent('');
+    expect(screen.queryByText('Invalid time')).not.toBeInTheDocument();
+  });
+
   it('calls onChange on blur when input is valid', async () => {
     const user = userEvent.setup();
     const onChange = vi.fn();
diff --git a/packages/core/src/TimeInput/TimeInput.tsx b/packages/core/src/TimeInput/TimeInput.tsx
index 1939ede5853d..9de7ebc8ecbc 100644
--- a/packages/core/src/TimeInput/TimeInput.tsx
+++ b/packages/core/src/TimeInput/TimeInput.tsx
@@ -635,7 +635,9 @@ export function TimeInput({
         data-autofocus={hasAutoFocus || undefined}
         aria-describedby={ariaDescribedBy}
         aria-required={isRequired === true ? 'true' : undefined}
-        aria-invalid={status?.type === 'error' ? 'true' : undefined}
+        aria-invalid={
+          status?.type === 'error' || !isInputValid ? 'true' : undefined
+        }
         aria-busy={isBusy || undefined}
         aria-labelledby={ariaLabelledBy}
         {...stylex.props(
@@ -644,6 +646,14 @@ export function TimeInput({
           !isInputValid && styles.inputInvalid,
         )}
       />
+      {/*
+          Live region announcing invalid typed input to assistive technology.
+          The value silently reverts on blur, so without this a screen-reader
+          user would get no feedback that their entry was rejected (WCAG 3.3.1).
+        */}
+      <VisuallyHidden as="div" role="alert" aria-live="assertive">
+        {!isInputValid ? 'Invalid time' : ''}
+      </VisuallyHidden>
       {isBusy && <Spinner size="sm" />}
       {hasClear && value && !isDisabled && (
         <button