diff --git a/docs/CONTRIBUTING.md b/docs/CONTRIBUTING.md
index 6d85f5cd..bd80c187 100644
--- a/docs/CONTRIBUTING.md
+++ b/docs/CONTRIBUTING.md
@@ -299,7 +299,7 @@ the source to the output or vice versa.
 ### Reporting a website bug
 
 If the bug is in the documentation (anything under `/docs/`) then please see the
-section above.  Bugs in the rest of the site are reported to to the [website
+section above.  Bugs in the rest of the site are reported to the [website
 source repository](https://github.com/glfw/website/issues).
 
 
diff --git a/docs/Doxyfile.in b/docs/Doxyfile.in
index 51f2b093..ec1c382e 100644
--- a/docs/Doxyfile.in
+++ b/docs/Doxyfile.in
@@ -264,7 +264,7 @@ MARKDOWN_SUPPORT       = YES
 
 # When enabled doxygen tries to link words that correspond to documented classes,
 # or namespaces to their corresponding documentation. Such a link can be
-# prevented in individual cases by by putting a % sign in front of the word or
+# prevented in individual cases by putting a % sign in front of the word or
 # globally by setting AUTOLINK_SUPPORT to NO.
 
 AUTOLINK_SUPPORT       = YES
diff --git a/docs/input.dox b/docs/input.dox
index 8cd37917..8f069a7e 100644
--- a/docs/input.dox
+++ b/docs/input.dox
@@ -523,7 +523,7 @@ int present = glfwJoystickPresent(GLFW_JOYSTICK_1);
 Each joystick has zero or more axes, zero or more buttons, zero or more hats,
 a human-readable name, a user pointer and an SDL compatible GUID.
 
-When GLFW is initialized, detected joysticks are added to to the beginning of
+When GLFW is initialized, detected joysticks are added to the beginning of
 the array.  Once a joystick is detected, it keeps its assigned ID until it is
 disconnected or the library is terminated, so as joysticks are connected and
 disconnected, there may appear gaps in the IDs.
diff --git a/docs/monitor.dox b/docs/monitor.dox
index 08c11933..b23482b6 100644
--- a/docs/monitor.dox
+++ b/docs/monitor.dox
@@ -101,7 +101,7 @@ size and a gamma ramp.
 @subsection monitor_modes Video modes
 
 GLFW generally does a good job selecting a suitable video mode when you create
-a full screen window, change its video mode or or make a windowed one full
+a full screen window, change its video mode or make a windowed one full
 screen, but it is sometimes useful to know exactly which video modes are
 supported.