diff --git a/examples/flutter_gallery/lib/demo/animation/home.dart b/examples/flutter_gallery/lib/demo/animation/home.dart
index f8e81709b0f..f660a2a959e 100644
--- a/examples/flutter_gallery/lib/demo/animation/home.dart
+++ b/examples/flutter_gallery/lib/demo/animation/home.dart
@@ -407,7 +407,7 @@ class _SnappingScrollPhysics extends ClampingScrollPhysics {
         return _toZeroScrollOffsetSimulation(offset, dragVelocity);
     } else {
       // The user ended the drag with little or no velocity. If they
-      // didn't leave the the offset above midScrollOffset, then
+      // didn't leave the offset above midScrollOffset, then
       // snap to midScrollOffset if they're more than halfway there,
       // otherwise snap to zero.
       final double snapThreshold = midScrollOffset / 2.0;
diff --git a/packages/flutter/lib/src/gestures/velocity_tracker.dart b/packages/flutter/lib/src/gestures/velocity_tracker.dart
index a02608444cc..93f45229b03 100644
--- a/packages/flutter/lib/src/gestures/velocity_tracker.dart
+++ b/packages/flutter/lib/src/gestures/velocity_tracker.dart
@@ -79,7 +79,7 @@ class Velocity {
 /// A two dimensional velocity estimate.
 ///
 /// VelocityEstimates are computed by [VelocityTracker.getVelocityEstimate]. An
-/// estimate's [confidence] measures how well the the velocity tracker's position
+/// estimate's [confidence] measures how well the velocity tracker's position
 /// data fit a straight line, [duration] is the time that elapsed between the
 /// first and last position sample used to compute the velocity, and [offset]
 /// is similarly the difference between the first and last positions.
diff --git a/packages/flutter/lib/src/material/app_bar.dart b/packages/flutter/lib/src/material/app_bar.dart
index 2fbd6386ed1..336811f7a3c 100644
--- a/packages/flutter/lib/src/material/app_bar.dart
+++ b/packages/flutter/lib/src/material/app_bar.dart
@@ -209,7 +209,7 @@ class AppBar extends StatefulWidget implements PreferredSizeWidget {
   final List<Widget> actions;
 
   /// This widget is stacked behind the toolbar and the tabbar. It's height will
-  /// be the same as the the app bar's overall height.
+  /// be the same as the app bar's overall height.
   ///
   /// A flexible space isn't actually flexible unless the [AppBar]'s container
   /// changes the [AppBar]'s size. A [SliverAppBar] in a [CustomScrollView]
@@ -795,7 +795,7 @@ class SliverAppBar extends StatefulWidget {
   final List<Widget> actions;
 
   /// This widget is stacked behind the toolbar and the tabbar. It's height will
-  /// be the same as the the app bar's overall height.
+  /// be the same as the app bar's overall height.
   ///
   /// Typically a [FlexibleSpaceBar]. See [FlexibleSpaceBar] for details.
   final Widget flexibleSpace;
diff --git a/packages/flutter/lib/src/material/button.dart b/packages/flutter/lib/src/material/button.dart
index 8c2e41967ab..e1311423cd3 100644
--- a/packages/flutter/lib/src/material/button.dart
+++ b/packages/flutter/lib/src/material/button.dart
@@ -229,7 +229,7 @@ class MaterialButton extends StatelessWidget {
   /// The color to use for this button's text.
   final Color textColor;
 
-  /// The the button's fill color, displayed by its [Material], while the button
+  /// The button's fill color, displayed by its [Material], while the button
   /// is in its default (unpressed, enabled) state.
   ///
   /// Defaults to null, meaning that the color is automatically derived from the [Theme].
diff --git a/packages/flutter/lib/src/material/tabs.dart b/packages/flutter/lib/src/material/tabs.dart
index 03a0a04e2f0..a9ea649b4cf 100644
--- a/packages/flutter/lib/src/material/tabs.dart
+++ b/packages/flutter/lib/src/material/tabs.dart
@@ -446,7 +446,7 @@ class _DragAnimation extends Animation<double> with AnimationWithParentMixin<dou
   }
 }
 
-// This class, and TabBarScrollController, only exist to handle the the case
+// This class, and TabBarScrollController, only exist to handle the case
 // where a scrollable TabBar has a non-zero initialIndex. In that case we can
 // only compute the scroll position's initial scroll offset (the "correct"
 // pixels value) after the TabBar viewport width and scroll limits are known.
@@ -476,7 +476,7 @@ class _TabBarScrollPosition extends ScrollPositionWithSingleContext {
   }
 }
 
-// This class, and TabBarScrollPosition, only exist to handle the the case
+// This class, and TabBarScrollPosition, only exist to handle the case
 // where a scrollable TabBar has a non-zero initialIndex.
 class _TabBarScrollController extends ScrollController {
   _TabBarScrollController(this.tabBar);
diff --git a/packages/flutter/lib/src/painting/borders.dart b/packages/flutter/lib/src/painting/borders.dart
index 3ce7a2fb3ea..eb0f934f44c 100644
--- a/packages/flutter/lib/src/painting/borders.dart
+++ b/packages/flutter/lib/src/painting/borders.dart
@@ -135,7 +135,7 @@ class BorderSide {
   ///
   /// The `t` argument represents the multiplicand, or the position on the
   /// timeline for an interpolation from nothing to `this`, with 0.0 meaning
-  /// that the the object returned should be the nil variant of this object, 1.0
+  /// that the object returned should be the nil variant of this object, 1.0
   /// meaning that no change should be applied, returning `this` (or something
   /// equivalent to `this`), and other values meaning that the object should be
   /// multiplied by `t`. Negative values are treated like zero.
@@ -328,7 +328,7 @@ abstract class ShapeBorder {
   ///
   /// The `t` argument represents the multiplicand, or the position on the
   /// timeline for an interpolation from nothing to `this`, with 0.0 meaning
-  /// that the the object returned should be the nil variant of this object, 1.0
+  /// that the object returned should be the nil variant of this object, 1.0
   /// meaning that no change should be applied, returning `this` (or something
   /// equivalent to `this`), and other values meaning that the object should be
   /// multiplied by `t`. Negative values are allowed but may be meaningless
diff --git a/packages/flutter/lib/src/rendering/flex.dart b/packages/flutter/lib/src/rendering/flex.dart
index 2abe6554b67..a515b60305c 100644
--- a/packages/flutter/lib/src/rendering/flex.dart
+++ b/packages/flutter/lib/src/rendering/flex.dart
@@ -642,7 +642,7 @@ class RenderFlex extends RenderBox with ContainerRenderObjectMixin<RenderBox, Fl
     final bool canFlex = maxMainSize < double.INFINITY;
 
     double crossSize = 0.0;
-    double allocatedSize = 0.0; // Sum of the sizes of the the non-flexible children.
+    double allocatedSize = 0.0; // Sum of the sizes of the non-flexible children.
     RenderBox child = firstChild;
     RenderBox lastFlexChild;
     while (child != null) {
diff --git a/packages/flutter/lib/src/rendering/object.dart b/packages/flutter/lib/src/rendering/object.dart
index e9392965247..68d97e45bc5 100644
--- a/packages/flutter/lib/src/rendering/object.dart
+++ b/packages/flutter/lib/src/rendering/object.dart
@@ -1854,7 +1854,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   /// Mark this render object as having changed its visual appearance.
   ///
   /// Rather than eagerly updating this render object's display list
-  /// in response to writes, we instead mark the the render object as needing to
+  /// in response to writes, we instead mark the render object as needing to
   /// paint, which schedules a visual update. As part of the visual update, the
   /// rendering pipeline will give this render object an opportunity to update
   /// its display list.
diff --git a/packages/flutter/lib/src/rendering/table_border.dart b/packages/flutter/lib/src/rendering/table_border.dart
index 8f9c0087efd..1a701f38fa8 100644
--- a/packages/flutter/lib/src/rendering/table_border.dart
+++ b/packages/flutter/lib/src/rendering/table_border.dart
@@ -120,7 +120,7 @@ class TableBorder {
   ///
   /// The `t` argument represents the multiplicand, or the position on the
   /// timeline for an interpolation from nothing to `this`, with 0.0 meaning
-  /// that the the object returned should be the nil variant of this object, 1.0
+  /// that the object returned should be the nil variant of this object, 1.0
   /// meaning that no change should be applied, returning `this` (or something
   /// equivalent to `this`), and other values meaning that the object should be
   /// multiplied by `t`. Negative values are treated like zero.
diff --git a/packages/flutter/lib/src/services/text_editing.dart b/packages/flutter/lib/src/services/text_editing.dart
index c044cf578cf..dee4bff5eb6 100644
--- a/packages/flutter/lib/src/services/text_editing.dart
+++ b/packages/flutter/lib/src/services/text_editing.dart
@@ -147,7 +147,7 @@ class TextSelection extends TextRange {
   /// Might be larger than, smaller than, or equal to base.
   final int extentOffset;
 
-  /// If the the text range is collapsed and has more than one visual location
+  /// If the text range is collapsed and has more than one visual location
   /// (e.g., occurs at a line break), which of the two locations to use when
   /// painting the caret.
   final TextAffinity affinity;
diff --git a/packages/flutter/lib/src/widgets/app.dart b/packages/flutter/lib/src/widgets/app.dart
index 7c067280561..37a41310eba 100644
--- a/packages/flutter/lib/src/widgets/app.dart
+++ b/packages/flutter/lib/src/widgets/app.dart
@@ -344,7 +344,7 @@ class WidgetsApp extends StatefulWidget {
   /// inspect modes.
   ///
   /// This lets [MaterialApp] to use a material button to toggle the inspector
-  /// select mode without requiring [WidgetInspector] to depend on the the
+  /// select mode without requiring [WidgetInspector] to depend on the
   /// material package.
   final InspectorSelectButtonBuilder inspectorSelectButtonBuilder;
 
diff --git a/packages/flutter/lib/src/widgets/dismissible.dart b/packages/flutter/lib/src/widgets/dismissible.dart
index 89d4d87f27c..6f1751b9241 100644
--- a/packages/flutter/lib/src/widgets/dismissible.dart
+++ b/packages/flutter/lib/src/widgets/dismissible.dart
@@ -115,7 +115,7 @@ class Dismissible extends StatefulWidget {
   /// The amount of time the widget will spend contracting before [onDismissed] is called.
   ///
   /// If null, the widget will not contract and [onDismissed] will be called
-  /// immediately after the the widget is dismissed.
+  /// immediately after the widget is dismissed.
   final Duration resizeDuration;
 
   /// The offset threshold the item has to be dragged in order to be considered
diff --git a/packages/flutter/lib/src/widgets/page_storage.dart b/packages/flutter/lib/src/widgets/page_storage.dart
index b4b43dba954..6e99610a74c 100644
--- a/packages/flutter/lib/src/widgets/page_storage.dart
+++ b/packages/flutter/lib/src/widgets/page_storage.dart
@@ -20,7 +20,7 @@ import 'framework.dart';
 ///
 /// For example, to ensure that the scroll offsets for the scrollable within
 /// each `MyScrollableTabView` below are restored when the [TabBarView]
-/// is recreated, we've specified [PageStorageKey]s whose values are the the
+/// is recreated, we've specified [PageStorageKey]s whose values are the
 /// tabs' string labels.
 ///
 /// ```dart
diff --git a/packages/flutter/lib/src/widgets/scroll_physics.dart b/packages/flutter/lib/src/widgets/scroll_physics.dart
index cd74df225f1..957616f8fd6 100644
--- a/packages/flutter/lib/src/widgets/scroll_physics.dart
+++ b/packages/flutter/lib/src/widgets/scroll_physics.dart
@@ -241,7 +241,7 @@ class ScrollPhysics {
 ///
 /// See also:
 ///
-///  * [ScrollConfiguration], which uses this to provide the the default
+///  * [ScrollConfiguration], which uses this to provide the default
 ///    scroll behavior on iOS.
 ///  * [ClampingScrollPhysics], which is the analogous physics for Android's
 ///    clamping behavior.
@@ -356,7 +356,7 @@ class BouncingScrollPhysics extends ScrollPhysics {
 ///
 /// See also:
 ///
-///  * [ScrollConfiguration], which uses this to provide the the default
+///  * [ScrollConfiguration], which uses this to provide the default
 ///    scroll behavior on Android.
 ///  * [BouncingScrollPhysics], which is the analogous physics for iOS' bouncing
 ///    behavior.
diff --git a/packages/flutter/lib/src/widgets/text_selection.dart b/packages/flutter/lib/src/widgets/text_selection.dart
index 31675296961..b6524031001 100644
--- a/packages/flutter/lib/src/widgets/text_selection.dart
+++ b/packages/flutter/lib/src/widgets/text_selection.dart
@@ -130,7 +130,7 @@ abstract class TextSelectionControls {
     return true;
   }
 
-  /// Whether the the current selection of the text field managed by the given
+  /// Whether the current selection of the text field managed by the given
   /// `delegate` can be extended to include the entire content of the text
   /// field.
   ///
diff --git a/packages/flutter/lib/src/widgets/widget_inspector.dart b/packages/flutter/lib/src/widgets/widget_inspector.dart
index 73bfbd87d55..a35abfe47c6 100644
--- a/packages/flutter/lib/src/widgets/widget_inspector.dart
+++ b/packages/flutter/lib/src/widgets/widget_inspector.dart
@@ -1061,7 +1061,7 @@ const TextStyle _messageStyle = const TextStyle(
 /// constructor was called from.
 ///
 /// A [Dart Kernel Transformer](https://github.com/dart-lang/sdk/wiki/Kernel-Documentation).
-/// adds this interface to the [Widget] class when the the
+/// adds this interface to the [Widget] class when the
 /// `--track-widget-creation` flag is passed to `flutter_tool`. Dart 2.0 is
 /// required as injecting creation locations requires a
 /// [Dart Kernel Transformer](https://github.com/dart-lang/sdk/wiki/Kernel-Documentation).
diff --git a/packages/flutter/test/material/app_bar_test.dart b/packages/flutter/test/material/app_bar_test.dart
index 0b7e60e2493..64783b51a8b 100644
--- a/packages/flutter/test/material/app_bar_test.dart
+++ b/packages/flutter/test/material/app_bar_test.dart
@@ -700,7 +700,7 @@ void main() {
     expect(appBarTop(tester), lessThanOrEqualTo(-128.0));
 
     // Drag the scrollable up and down. The app bar should not snap open, its
-    // height should just track the the drag offset.
+    // height should just track the drag offset.
     TestGesture gesture = await tester.startGesture(const Offset(50.0, 256.0));
     await gesture.moveBy(const Offset(0.0, 128.0)); // drag the appbar all the way open
     await tester.pump();
diff --git a/packages/flutter/test/material/modal_bottom_sheet_test.dart b/packages/flutter/test/material/modal_bottom_sheet_test.dart
index 9b84f419990..0881a40f7ff 100644
--- a/packages/flutter/test/material/modal_bottom_sheet_test.dart
+++ b/packages/flutter/test/material/modal_bottom_sheet_test.dart
@@ -37,7 +37,7 @@ void main() {
     expect(find.text('BottomSheet'), findsOneWidget);
     expect(showBottomSheetThenCalled, isFalse);
 
-    // Tap on the the bottom sheet itself to dismiss it
+    // Tap on the bottom sheet itself to dismiss it
     await tester.tap(find.text('BottomSheet'));
     await tester.pump(); // bottom sheet dismiss animation starts
     expect(showBottomSheetThenCalled, isTrue);
@@ -58,7 +58,7 @@ void main() {
     expect(find.text('BottomSheet'), findsOneWidget);
     expect(showBottomSheetThenCalled, isFalse);
 
-    // Tap above the the bottom sheet to dismiss it
+    // Tap above the bottom sheet to dismiss it
     await tester.tapAt(const Offset(20.0, 20.0));
     await tester.pump(); // bottom sheet dismiss animation starts
     expect(showBottomSheetThenCalled, isTrue);
diff --git a/packages/flutter/test/widgets/custom_painter_test.dart b/packages/flutter/test/widgets/custom_painter_test.dart
index b3da2ae0993..8484293430b 100644
--- a/packages/flutter/test/widgets/custom_painter_test.dart
+++ b/packages/flutter/test/widgets/custom_painter_test.dart
@@ -597,7 +597,7 @@ class _DiffTester {
 
   /// Creates an initial semantics list using the `from` list, then updates the
   /// list to the `to` list. This causes [RenderCustomPaint] to diff the two
-  /// lists and apply the changes. This method asserts the the changes were
+  /// lists and apply the changes. This method asserts the changes were
   /// applied correctly, specifically:
   ///
   /// - checks that initial and final configurations are in the desired states.