diff --git a/INSTALL.in b/INSTALL.in
index ef4bb0d4a2..14fb596481 100644
--- a/INSTALL.in
+++ b/INSTALL.in
@@ -59,7 +59,7 @@ help in that regard:
      GIR data is when cross-compiling because of the difficulty to make cross-tools
      for GObject Introspection.
      Nevertheless if you have working GIR cross-tools, you can force the expected
-     behaviour with GIMP's meson option -Dcan-crosscompile-gir=true
+     behavior with GIMP's meson option -Dcan-crosscompile-gir=true
 
      Optional:
 
diff --git a/app/config/gimprc-blurbs.h b/app/config/gimprc-blurbs.h
index 61a9bed078..ca7e211a36 100644
--- a/app/config/gimprc-blurbs.h
+++ b/app/config/gimprc-blurbs.h
@@ -325,7 +325,7 @@ _("When enabled, non-visible layers can be edited as normal.")
 
 #define MOVE_TOOL_CHANGES_ACTIVE_BLURB \
 _("If enabled, the move tool sets the edited layer or path as active.  " \
-  "This used to be the default behaviour in older versions.")
+  "This used to be the default behavior in older versions.")
 
 #define MYPAINT_BRUSH_PATH_BLURB \
 "Sets the brush search path."
diff --git a/app/dialogs/preferences-dialog.c b/app/dialogs/preferences-dialog.c
index cecc2cd4d7..b8a495d8e8 100644
--- a/app/dialogs/preferences-dialog.c
+++ b/app/dialogs/preferences-dialog.c
@@ -1531,7 +1531,7 @@ prefs_dialog_new (Gimp       *gimp,
     grid = prefs_grid_new (GTK_CONTAINER (vbox2));
 
     button = prefs_enum_combo_box_add (object, "color-profile-policy", 0, 0,
-                                       _("_File Open behaviour:"),
+                                       _("_File Open behavior:"),
                                        GTK_GRID (grid), 0, size_group);
 
     /*  Filter Dialogs  */
diff --git a/app/display/gimptoolrectangle.c b/app/display/gimptoolrectangle.c
index 2b16b87c31..7fc4a7b30a 100644
--- a/app/display/gimptoolrectangle.c
+++ b/app/display/gimptoolrectangle.c
@@ -3860,7 +3860,7 @@ gimp_tool_rectangle_update_int_rect (GimpToolRectangle *rectangle)
  * @ccoord_x_output:
  * @ccoord_x_output:
  *
- * Transforms a coordinate to better fit the public behaviour of the
+ * Transforms a coordinate to better fit the public behavior of the
  * rectangle.
  */
 static void
diff --git a/app/pdb/image-undo-cmds.c b/app/pdb/image-undo-cmds.c
index a6046714e7..22ae47eef2 100644
--- a/app/pdb/image-undo-cmds.c
+++ b/app/pdb/image-undo-cmds.c
@@ -427,7 +427,7 @@ register_image_undo_procs (GimpPDB *pdb)
                                "gimp-image-undo-freeze");
   gimp_procedure_set_static_help (procedure,
                                   "Freeze the image's undo stack.",
-                                  "This procedure freezes the image's undo stack, allowing subsequent operations to ignore their undo steps. This is generally called in conjunction with 'gimp-image-undo-thaw' to temporarily disable an image undo stack. This is advantageous because saving undo steps can be time and memory intensive. 'gimp-image-undo-freeze' / 'gimp-image-undo-thaw' and 'gimp-image-undo-disable' / 'gimp-image-undo-enable' differ in that the former does not free up all undo steps when undo is thawed, so is more suited to interactive in-situ previews. It is important in this case that the image is back to the same state it was frozen in before thawing, else 'undo' behaviour is undefined.",
+                                  "This procedure freezes the image's undo stack, allowing subsequent operations to ignore their undo steps. This is generally called in conjunction with 'gimp-image-undo-thaw' to temporarily disable an image undo stack. This is advantageous because saving undo steps can be time and memory intensive. 'gimp-image-undo-freeze' / 'gimp-image-undo-thaw' and 'gimp-image-undo-disable' / 'gimp-image-undo-enable' differ in that the former does not free up all undo steps when undo is thawed, so is more suited to interactive in-situ previews. It is important in this case that the image is back to the same state it was frozen in before thawing, else 'undo' behavior is undefined.",
                                   NULL);
   gimp_procedure_set_static_attribution (procedure,
                                          "Adam D. Moss",
diff --git a/app/widgets/gimpactionimpl.c b/app/widgets/gimpactionimpl.c
index 9581ed8994..5d5bd1e4bb 100644
--- a/app/widgets/gimpactionimpl.c
+++ b/app/widgets/gimpactionimpl.c
@@ -308,7 +308,7 @@ gimp_action_impl_change_state (GAction  *action,
   if (g_signal_has_handler_pending (action, gimp_action_impl_signals[CHANGE_STATE], 0, TRUE))
     g_signal_emit (action, gimp_action_impl_signals[CHANGE_STATE], 0, value);
   else
-    /* If not, then the default behaviour is to just set the state. */
+    /* If not, then the default behavior is to just set the state. */
     gimp_action_impl_set_state (GIMP_ACTION (action), value);
 }
 
diff --git a/docs/gimprc.5.in b/docs/gimprc.5.in
index 14032a4879..1fd61e6294 100644
--- a/docs/gimprc.5.in
+++ b/docs/gimprc.5.in
@@ -858,7 +858,7 @@ yes and no.
 (move-tool-changes-active no)
 
 If enabled, the move tool sets the edited layer or path as active.  This used
-to be the default behaviour in older versions.  Possible values are yes and
+to be the default behavior in older versions.  Possible values are yes and
 no.
 
 .TP
diff --git a/etc/gimprc.in b/etc/gimprc.in
index 3d6e1e7923..dbc9756072 100644
--- a/etc/gimprc.in
+++ b/etc/gimprc.in
@@ -669,7 +669,7 @@
 # (edit-non-visible no)
 
 # If enabled, the move tool sets the edited layer or path as active.  This
-# used to be the default behaviour in older versions.  Possible values are
+# used to be the default behavior in older versions.  Possible values are
 # yes and no.
 # 
 # (move-tool-changes-active no)
diff --git a/libgimp/gimpimageundo_pdb.c b/libgimp/gimpimageundo_pdb.c
index 25069334aa..c3d7c2e3f3 100644
--- a/libgimp/gimpimageundo_pdb.c
+++ b/libgimp/gimpimageundo_pdb.c
@@ -234,7 +234,7 @@ gimp_image_undo_enable (GimpImage *image)
  * all undo steps when undo is thawed, so is more suited to interactive
  * in-situ previews. It is important in this case that the image is
  * back to the same state it was frozen in before thawing, else 'undo'
- * behaviour is undefined.
+ * behavior is undefined.
  *
  * Returns: TRUE if the image undo has been frozen.
  **/
diff --git a/libgimpwidgets/gimpcolorarea.c b/libgimpwidgets/gimpcolorarea.c
index d42e839ebb..841f2a41f0 100644
--- a/libgimpwidgets/gimpcolorarea.c
+++ b/libgimpwidgets/gimpcolorarea.c
@@ -652,7 +652,7 @@ gimp_color_area_enable_drag (GimpColorArea   *area,
  * @draw_border: whether to draw a border or not
  *
  * The @area can draw a thin border in the foreground color around
- * itself.  This function toggles this behaviour on and off. The
+ * itself.  This function toggles this behavior on and off. The
  * default is not draw a border.
  **/
 void
diff --git a/libgimpwidgets/gimplabelcolor.c b/libgimpwidgets/gimplabelcolor.c
index 19a95d65e1..3a7dc6faaf 100644
--- a/libgimpwidgets/gimplabelcolor.c
+++ b/libgimpwidgets/gimplabelcolor.c
@@ -320,7 +320,7 @@ gimp_label_color_populate (GimpLabeled *labeled,
  * In the editable case, the @label is reused as the color chooser's
  * dialog title.
  *
- * If you wish to customize any of these default behaviours, get the
+ * If you wish to customize any of these default behaviors, get the
  * #GimpColorArea or #GimpColorButton with gimp_label_color_get_color_widget().
  *
  * Returns: (transfer full): The new #GimpLabelColor widget.
diff --git a/libgimpwidgets/gimppreview.c b/libgimpwidgets/gimppreview.c
index dbef1d282b..65a692a644 100644
--- a/libgimpwidgets/gimppreview.c
+++ b/libgimpwidgets/gimppreview.c
@@ -862,7 +862,7 @@ gimp_preview_get_area (GimpPreview  *preview)
  * @preview: a #GimpPreview widget
  *
  * Calls the GimpPreview::draw method. GimpPreview itself doesn't
- * implement a default draw method so the behaviour is determined by
+ * implement a default draw method so the behavior is determined by
  * the derived class implementing this method.
  *
  * #GimpDrawablePreview implements gimp_preview_draw() by drawing the
@@ -886,7 +886,7 @@ gimp_preview_draw (GimpPreview *preview)
  * @rowstride: the @buffer's rowstride
  *
  * Calls the GimpPreview::draw_buffer method. GimpPreview itself
- * doesn't implement this method so the behaviour is determined by the
+ * doesn't implement this method so the behavior is determined by the
  * derived class implementing this method.
  *
  * Since: 2.2
diff --git a/libgimpwidgets/gimpscaleentry.c b/libgimpwidgets/gimpscaleentry.c
index ee6e1f94fd..c223d4c087 100644
--- a/libgimpwidgets/gimpscaleentry.c
+++ b/libgimpwidgets/gimpscaleentry.c
@@ -401,7 +401,7 @@ gimp_scale_entry_set_bounds (GimpScaleEntry *entry,
 /**
  * gimp_scale_entry_set_logarithmic:
  * @entry:       a #GimpScaleEntry as returned by gimp_scale_entry_new()
- * @logarithmic: a boolean value to set or reset logarithmic behaviour
+ * @logarithmic: a boolean value to set or reset logarithmic behavior
  *               of the scale widget
  *
  * Sets whether @entry's scale widget will behave in a linear
@@ -433,7 +433,7 @@ gimp_scale_entry_set_logarithmic (GimpScaleEntry *entry,
  * @entry: a #GimpScaleEntry as returned by gimp_scale_entry_new()
  *
  * Returns: %TRUE if @entry's scale widget will behave in
- *          logarithmic fashion, %FALSE for linear behaviour.
+ *          logarithmic fashion, %FALSE for linear behavior.
  *
  * Since: 2.2
  **/
diff --git a/plug-ins/common/file-pdf-save.c b/plug-ins/common/file-pdf-save.c
index 3b83b6fcac..25cbc287df 100644
--- a/plug-ins/common/file-pdf-save.c
+++ b/plug-ins/common/file-pdf-save.c
@@ -70,7 +70,7 @@
  * May 6, 2009 Barak | Itkin <lightningismyname@gmail.com>
  *   Added new features and several bugfixes:
  *   - Added handling for image resolutions
- *   - fixed the behaviour of getting font sizes
+ *   - fixed the behavior of getting font sizes
  *   - Added various optimizations (solid rectangles instead of bitmaps, ignoring
  *     invisible layers, etc.) as a macro flag.
  *   - Added handling for layer masks, use CAIRO_FORMAT_A8 for grayscale drawables.
diff --git a/plug-ins/python/palette-sort.py b/plug-ins/python/palette-sort.py
index d93d098ddf..8fb9d02f0e 100755
--- a/plug-ins/python/palette-sort.py
+++ b/plug-ins/python/palette-sort.py
@@ -251,7 +251,7 @@ def palette_sort(palette, selection, slice_expr, channel1, ascending1,
         except ValueError:
             # bad expression is okay here, just assume one row
             nrows = 1
-        # remaining behaviour is implemented by SELECT_SLICE 'inheritance'.
+        # remaining behavior is implemented by SELECT_SLICE 'inheritance'.
         selection = SELECT_SLICE
     elif selection in (SELECT_SLICE, SELECT_PARTITIONED):
         start, nrows, length = parse_slice(slice_expr, num_colors)
diff --git a/tools/gimptool.c b/tools/gimptool.c
index 22fbd68148..b3b754f48e 100644
--- a/tools/gimptool.c
+++ b/tools/gimptool.c
@@ -997,7 +997,7 @@ main (int    argc,
   if (argc == 1)
     usage (EXIT_SUCCESS);
 
-  /* First scan for flags that affect our behaviour globally, but
+  /* First scan for flags that affect our behavior globally, but
    * are still allowed late on the command line.
    */
   argi = 0;