diff --git a/dev/bots/prepare_package.dart b/dev/bots/prepare_package.dart
index b45bb1d6d6..fd61989093 100644
--- a/dev/bots/prepare_package.dart
+++ b/dev/bots/prepare_package.dart
@@ -110,7 +110,7 @@ class ProcessRunner {
   /// [Directory.current] if [defaultWorkingDirectory] is not set.
   ///
   /// Set `failOk` if [runProcess] should not throw an exception when the
-  /// command completes with a a non-zero exit code.
+  /// command completes with a non-zero exit code.
   Future<String> runProcess(
     List<String> commandLine, {
     Directory workingDirectory,
diff --git a/dev/bots/unpublish_package.dart b/dev/bots/unpublish_package.dart
index 5385ec2b22..a007041b11 100644
--- a/dev/bots/unpublish_package.dart
+++ b/dev/bots/unpublish_package.dart
@@ -145,7 +145,7 @@ class ProcessRunner {
   /// [Directory.current] if [defaultWorkingDirectory] is not set.
   ///
   /// Set `failOk` if [runProcess] should not throw an exception when the
-  /// command completes with a a non-zero exit code.
+  /// command completes with a non-zero exit code.
   Future<String> runProcess(
     List<String> commandLine, {
     Directory workingDirectory,
diff --git a/dev/integration_tests/ios_add2app/README.md b/dev/integration_tests/ios_add2app/README.md
index 78037466b6..7ab05bb13e 100644
--- a/dev/integration_tests/ios_add2app/README.md
+++ b/dev/integration_tests/ios_add2app/README.md
@@ -13,7 +13,7 @@ The following functionality is currently implemented:
    (FullScreenViewController.m).
 1. A demo of pushing a FlutterViewController on as a child view.
 1. A demo of showing both the native and the Flutter views using a platform
-   channel to to interact with each other (HybridViewController.m).
+   channel to interact with each other (HybridViewController.m).
 1. A demo of showing two FlutterViewControllers simultaneously
    (DualViewController.m).
 
diff --git a/dev/integration_tests/ios_add2app_life_cycle/README.md b/dev/integration_tests/ios_add2app_life_cycle/README.md
index 351492bed2..9797ffed0e 100644
--- a/dev/integration_tests/ios_add2app_life_cycle/README.md
+++ b/dev/integration_tests/ios_add2app_life_cycle/README.md
@@ -13,7 +13,7 @@ The following functionality is currently implemented:
    (FullScreenViewController.m).
 1. A demo of pushing a FlutterViewController on as a child view.
 1. A demo of showing both the native and the Flutter views using a platform
-   channel to to interact with each other (HybridViewController.m).
+   channel to interact with each other (HybridViewController.m).
 1. A demo of showing two FlutterViewControllers simultaneously
    (DualViewController.m).
 
diff --git a/packages/flutter/lib/src/material/app_bar.dart b/packages/flutter/lib/src/material/app_bar.dart
index 30ea7fe4c8..9832bdff1b 100644
--- a/packages/flutter/lib/src/material/app_bar.dart
+++ b/packages/flutter/lib/src/material/app_bar.dart
@@ -297,7 +297,7 @@ class AppBar extends StatefulWidget implements PreferredSizeWidget {
   /// last action.
   ///
   /// The [actions] become the trailing component of the [NavigationToolBar] built
-  /// by this widget. The the height of each action is constrained to be no bigger
+  /// by this widget. The height of each action is constrained to be no bigger
   /// than the toolbar's height, which is [kToolbarHeight].
   final List<Widget> actions;
 
diff --git a/packages/flutter/lib/src/material/slider_theme.dart b/packages/flutter/lib/src/material/slider_theme.dart
index ac9a347725..7bcd6d32c9 100644
--- a/packages/flutter/lib/src/material/slider_theme.dart
+++ b/packages/flutter/lib/src/material/slider_theme.dart
@@ -578,7 +578,7 @@ class SliderThemeData extends Diagnosticable {
 
   /// The shape that will be used to draw the [RangeSlider]'s track.
   ///
-  /// The [SliderTrackShape.getPreferredRect] method is used to to map
+  /// The [SliderTrackShape.getPreferredRect] method is used to map
   /// slider-relative gesture coordinates to the correct thumb position on the
   /// track. It is also used to horizontally position the tick marks, when the
   /// slider is discrete.
diff --git a/packages/flutter/lib/src/painting/image_provider.dart b/packages/flutter/lib/src/painting/image_provider.dart
index 87c29fff53..0678319204 100644
--- a/packages/flutter/lib/src/painting/image_provider.dart
+++ b/packages/flutter/lib/src/painting/image_provider.dart
@@ -754,7 +754,7 @@ class ResizeImage extends ImageProvider<_SizeAwareCacheKey> {
     if (result != null) {
       return result;
     }
-    // If the code reaches here, it means the the imageProvider.obtainKey was not
+    // If the code reaches here, it means the imageProvider.obtainKey was not
     // completed sync, so we initialize the completer for completion later.
     completer = Completer<_SizeAwareCacheKey>();
     return completer.future;
diff --git a/packages/flutter/lib/src/widgets/focus_scope.dart b/packages/flutter/lib/src/widgets/focus_scope.dart
index a4825ee82e..c173c977ff 100644
--- a/packages/flutter/lib/src/widgets/focus_scope.dart
+++ b/packages/flutter/lib/src/widgets/focus_scope.dart
@@ -372,7 +372,7 @@ class Focus extends StatefulWidget {
   /// If true, this [Focus] widget will include a [Semantics] node that
   /// indicates the [Semantics.focusable] and [Semantics.focused] properties.
   ///
-  /// Is is not typical to set this to false, as that can affect the semantics
+  /// It is not typical to set this to false, as that can affect the semantics
   /// information available to accessibility systems.
   ///
   /// Must not be null, defaults to true.
diff --git a/packages/flutter/test/material/bottom_app_bar_test.dart b/packages/flutter/test/material/bottom_app_bar_test.dart
index 582ac0c589..18eb488b29 100644
--- a/packages/flutter/test/material/bottom_app_bar_test.dart
+++ b/packages/flutter/test/material/bottom_app_bar_test.dart
@@ -384,7 +384,7 @@ void main() {
 
 // The bottom app bar clip path computation is only available at paint time.
 // In order to examine the notch path we implement this caching painter which
-// at paint time looks for for a descendant PhysicalShape and caches the
+// at paint time looks for a descendant PhysicalShape and caches the
 // clip path it is using.
 class ClipCachePainter extends CustomPainter {
   ClipCachePainter(this.context);
diff --git a/packages/flutter/test/widgets/widget_inspector_test.dart b/packages/flutter/test/widgets/widget_inspector_test.dart
index 8a75458def..a0b5b5cd2b 100644
--- a/packages/flutter/test/widgets/widget_inspector_test.dart
+++ b/packages/flutter/test/widgets/widget_inspector_test.dart
@@ -1919,7 +1919,7 @@ class TestWidgetInspectorService extends Object with WidgetInspectorService {
       // No new locations were rebuilt.
       expect(event, isNot(contains('newLocations')));
 
-      // Triggering a a rebuild of one widget in this app causes the whole app
+      // Triggering a rebuild of one widget in this app causes the whole app
       // to repaint.
       expect(data.length, equals(18));
 
diff --git a/packages/flutter_tools/lib/src/build_system/build_system.dart b/packages/flutter_tools/lib/src/build_system/build_system.dart
index 0ef578693e..18c2e0fd8c 100644
--- a/packages/flutter_tools/lib/src/build_system/build_system.dart
+++ b/packages/flutter_tools/lib/src/build_system/build_system.dart
@@ -379,7 +379,7 @@ class Environment {
 
   /// The `FLUTTER_ROOT` environment variable.
   ///
-  /// Defaults to to the value of [Cache.flutterRoot].
+  /// Defaults to the value of [Cache.flutterRoot].
   final Directory flutterRootDir;
 
   /// The `OUTPUT_DIR` environment variable.
diff --git a/packages/flutter_tools/lib/src/flutter_manifest.dart b/packages/flutter_tools/lib/src/flutter_manifest.dart
index cd1f69aca4..b86ca76af2 100644
--- a/packages/flutter_tools/lib/src/flutter_manifest.dart
+++ b/packages/flutter_tools/lib/src/flutter_manifest.dart
@@ -331,7 +331,7 @@ bool _validate(YamlMap manifest) {
   final List<String> errors = <String>[];
   for (final MapEntry<dynamic, dynamic> kvp in manifest.entries) {
     if (kvp.key is! String) {
-      errors.add('Expected YAML key to be a a string, but got ${kvp.key}.');
+      errors.add('Expected YAML key to be a string, but got ${kvp.key}.');
       continue;
     }
     switch (kvp.key as String) {
@@ -371,7 +371,7 @@ void _validateFlutter(YamlMap yaml, List<String> errors) {
   }
   for (final MapEntry<dynamic, dynamic> kvp in yaml.entries) {
     if (kvp.key is! String) {
-      errors.add('Expected YAML key to be a a string, but got ${kvp.key} (${kvp.value.runtimeType}).');
+      errors.add('Expected YAML key to be a string, but got ${kvp.key} (${kvp.value.runtimeType}).');
       continue;
     }
     switch (kvp.key as String) {
diff --git a/packages/flutter_tools/lib/src/windows/visual_studio_project.dart b/packages/flutter_tools/lib/src/windows/visual_studio_project.dart
index 785c73e984..47a4f87c65 100644
--- a/packages/flutter_tools/lib/src/windows/visual_studio_project.dart
+++ b/packages/flutter_tools/lib/src/windows/visual_studio_project.dart
@@ -29,7 +29,7 @@ class VisualStudioProject {
   /// The content of the project file.
   xml.XmlDocument content;
 
-  /// Whether or not the the project file was correctly parsed.
+  /// Whether or not the project file was correctly parsed.
   ///
   /// If false, this could indicate that the project file is damaged, or that
   /// it's an unsupported project type.