diff --git a/README.md b/README.md
index 41173f0f..e24293b5 100644
--- a/README.md
+++ b/README.md
@@ -124,6 +124,9 @@ information on what to include when reporting a bug.
 
 ## Changelog
 
+- Added `glfwSetX11SelectionString` and `glfwGetX11SelectionString`
+  native functions for accessing X11 primary selection as a supplement to
+  the clipboard on the X11 platform (#894)
 - Added `glfwGetError` function for querying the last error code and its
   description (#970)
 - Added `glfwUpdateGamepadMappings` function for importing gamepad mappings in
diff --git a/docs/news.dox b/docs/news.dox
index d8bb23a5..0fdb5a73 100644
--- a/docs/news.dox
+++ b/docs/news.dox
@@ -5,6 +5,15 @@
 @section news_33 Release notes for 3.3
 
 
+@subsection news_33_native_x11_selection X11 native Primary Selection access
+
+GLFW now supports X11 platform specific native functions for accessing
+the X11 primary selection, as a supplement to the clipboard on this
+platform. See @ref clipboard.
+
+@see @ref error_handling
+
+
 @subsection news_33_geterror Error query
 
 GLFW now supports querying the last error code for the calling thread and its
diff --git a/include/GLFW/glfw3native.h b/include/GLFW/glfw3native.h
index 982eaa65..ad7ccb57 100644
--- a/include/GLFW/glfw3native.h
+++ b/include/GLFW/glfw3native.h
@@ -289,6 +289,56 @@ GLFWAPI RROutput glfwGetX11Monitor(GLFWmonitor* monitor);
  *  @ingroup native
  */
 GLFWAPI Window glfwGetX11Window(GLFWwindow* window);
+
+/*! @brief Sets the current primary selection to the specified string.
+ *
+ *  @param[in] string A UTF-8 encoded string.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The specified string is copied before this function
+ *  returns.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwGetX11SelectionString
+ *  @sa glfwSetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI void glfwSetX11SelectionString(const char* string);
+
+/*! @brief Returns the contents of the current primary selection as a string.
+ *
+ *  If the selection is empty or if its contents cannot be converted, `NULL`
+ *  is returned and a @ref GLFW_FORMAT_UNAVAILABLE error is generated.
+ *
+ *  @return The contents of the selection as a UTF-8 encoded string, or `NULL`
+ *  if an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The returned string is allocated and freed by GLFW. You
+ *  should not free it yourself. It is valid until the next call to @ref
+ *  glfwGetX11SelectionString or @ref glfwSetX11SelectionString, or until the
+ *  library is terminated.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwSetX11SelectionString
+ *  @sa glfwGetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetX11SelectionString(void);
 #endif
 
 #if defined(GLFW_EXPOSE_NATIVE_GLX)
diff --git a/src/x11_init.c b/src/x11_init.c
index 402552bb..7acea707 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -611,6 +611,7 @@ static GLFWbool initExtensions(void)
     // ICCCM standard clipboard atoms
     _glfw.x11.TARGETS = XInternAtom(_glfw.x11.display, "TARGETS", False);
     _glfw.x11.MULTIPLE = XInternAtom(_glfw.x11.display, "MULTIPLE", False);
+    _glfw.x11.PRIMARY = XInternAtom(_glfw.x11.display, "PRIMARY", False);
     _glfw.x11.CLIPBOARD = XInternAtom(_glfw.x11.display, "CLIPBOARD", False);
 
     // Clipboard manager atoms
@@ -853,6 +854,7 @@ void _glfwPlatformTerminate(void)
         _glfw.x11.hiddenCursorHandle = (Cursor) 0;
     }
 
+    free(_glfw.x11.primarySelectionString);
     free(_glfw.x11.clipboardString);
 
     if (_glfw.x11.im)
diff --git a/src/x11_platform.h b/src/x11_platform.h
index e56630cf..e28127bc 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -161,6 +161,8 @@ typedef struct _GLFWlibraryX11
     XIM             im;
     // Most recent error code received by X error handler
     int             errorCode;
+    // Primary selection string (while the primary selection is owned)
+    char*           primarySelectionString;
     // Clipboard string (while the selection is owned)
     char*           clipboardString;
     // Key name string
@@ -214,6 +216,7 @@ typedef struct _GLFWlibraryX11
     Atom            TARGETS;
     Atom            MULTIPLE;
     Atom            CLIPBOARD;
+    Atom            PRIMARY;
     Atom            CLIPBOARD_MANAGER;
     Atom            SAVE_TARGETS;
     Atom            NULL_;
diff --git a/src/x11_window.c b/src/x11_window.c
index cdaac5f8..eacb7467 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -675,6 +675,8 @@ static Atom writeTargetToProperty(const XSelectionRequestEvent* request)
                              _glfw.x11.COMPOUND_STRING,
                              XA_STRING };
     const int formatCount = sizeof(formats) / sizeof(formats[0]);
+    char *selectionString = request->selection == _glfw.x11.PRIMARY ?
+            _glfw.x11.primarySelectionString : _glfw.x11.clipboardString;
 
     if (request->property == None)
     {
@@ -735,8 +737,8 @@ static Atom writeTargetToProperty(const XSelectionRequestEvent* request)
                                 targets[i],
                                 8,
                                 PropModeReplace,
-                                (unsigned char*) _glfw.x11.clipboardString,
-                                strlen(_glfw.x11.clipboardString));
+                                (unsigned char *) selectionString,
+                                strlen(selectionString));
             }
             else
                 targets[i + 1] = None;
@@ -787,8 +789,8 @@ static Atom writeTargetToProperty(const XSelectionRequestEvent* request)
                             request->target,
                             8,
                             PropModeReplace,
-                            (unsigned char*) _glfw.x11.clipboardString,
-                            strlen(_glfw.x11.clipboardString));
+                            (unsigned char *) selectionString,
+                            strlen(selectionString));
 
             return request->property;
         }
@@ -801,8 +803,17 @@ static Atom writeTargetToProperty(const XSelectionRequestEvent* request)
 
 static void handleSelectionClear(XEvent* event)
 {
-    free(_glfw.x11.clipboardString);
-    _glfw.x11.clipboardString = NULL;
+    const XSelectionClearEvent* request = &event->xselectionclear;
+    if (request->selection == _glfw.x11.PRIMARY)
+    {
+        free(_glfw.x11.primarySelectionString);
+        _glfw.x11.primarySelectionString = NULL;
+    }
+    else if (request->selection == _glfw.x11.CLIPBOARD)
+    {
+        free(_glfw.x11.clipboardString);
+        _glfw.x11.clipboardString = NULL;
+    }
 }
 
 static void handleSelectionRequest(XEvent* event)
@@ -823,6 +834,76 @@ static void handleSelectionRequest(XEvent* event)
     XSendEvent(_glfw.x11.display, request->requestor, False, 0, &reply);
 }
 
+static const char *getSelection(Atom selection, char **ptr)
+{
+    size_t i;
+    const Atom formats[] = { _glfw.x11.UTF8_STRING,
+                             _glfw.x11.COMPOUND_STRING,
+                             XA_STRING };
+    const size_t formatCount = sizeof(formats) / sizeof(formats[0]);
+
+    if (XGetSelectionOwner(_glfw.x11.display, selection) ==
+        _glfw.x11.helperWindowHandle)
+    {
+        // Instead of doing a large number of X round-trips just to put this
+        // string into a window property and then read it back, just return it
+        return *ptr;
+    }
+
+    free(*ptr);
+    *ptr = NULL;
+
+    for (i = 0;  i < formatCount;  i++)
+    {
+        char* data;
+        XEvent event;
+
+        XConvertSelection(_glfw.x11.display,
+                          selection,
+                          formats[i],
+                          _glfw.x11.GLFW_SELECTION,
+                          _glfw.x11.helperWindowHandle,
+                          CurrentTime);
+
+        while (!XCheckTypedWindowEvent(_glfw.x11.display,
+                                       _glfw.x11.helperWindowHandle,
+                                       SelectionNotify,
+                                       &event))
+        {
+            waitForEvent(NULL);
+        }
+
+        if (event.xselection.property == None)
+            continue;
+
+        if (_glfwGetWindowPropertyX11(event.xselection.requestor,
+                                      event.xselection.property,
+                                      event.xselection.target,
+                                      (unsigned char**) &data))
+        {
+            *ptr = strdup(data);
+        }
+
+        if (data)
+            XFree(data);
+
+        XDeleteProperty(_glfw.x11.display,
+                        event.xselection.requestor,
+                        event.xselection.property);
+
+        if (*ptr)
+            break;
+    }
+
+    if (*ptr == NULL)
+    {
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
+                        "X11: Failed to convert clipboard to string");
+    }
+
+    return *ptr;
+}
+
 // Make the specified window and its video mode active on its monitor
 //
 static GLFWbool acquireMonitor(_GLFWwindow* window)
@@ -2572,72 +2653,7 @@ void _glfwPlatformSetClipboardString(_GLFWwindow* window, const char* string)
 
 const char* _glfwPlatformGetClipboardString(_GLFWwindow* window)
 {
-    size_t i;
-    const Atom formats[] = { _glfw.x11.UTF8_STRING,
-                             _glfw.x11.COMPOUND_STRING,
-                             XA_STRING };
-    const size_t formatCount = sizeof(formats) / sizeof(formats[0]);
-
-    if (XGetSelectionOwner(_glfw.x11.display, _glfw.x11.CLIPBOARD) ==
-        _glfw.x11.helperWindowHandle)
-    {
-        // Instead of doing a large number of X round-trips just to put this
-        // string into a window property and then read it back, just return it
-        return _glfw.x11.clipboardString;
-    }
-
-    free(_glfw.x11.clipboardString);
-    _glfw.x11.clipboardString = NULL;
-
-    for (i = 0;  i < formatCount;  i++)
-    {
-        char* data;
-        XEvent event;
-
-        XConvertSelection(_glfw.x11.display,
-                          _glfw.x11.CLIPBOARD,
-                          formats[i],
-                          _glfw.x11.GLFW_SELECTION,
-                          _glfw.x11.helperWindowHandle,
-                          CurrentTime);
-
-        while (!XCheckTypedWindowEvent(_glfw.x11.display,
-                                       _glfw.x11.helperWindowHandle,
-                                       SelectionNotify,
-                                       &event))
-        {
-            waitForEvent(NULL);
-        }
-
-        if (event.xselection.property == None)
-            continue;
-
-        if (_glfwGetWindowPropertyX11(event.xselection.requestor,
-                                      event.xselection.property,
-                                      event.xselection.target,
-                                      (unsigned char**) &data))
-        {
-            _glfw.x11.clipboardString = strdup(data);
-        }
-
-        if (data)
-            XFree(data);
-
-        XDeleteProperty(_glfw.x11.display,
-                        event.xselection.requestor,
-                        event.xselection.property);
-
-        if (_glfw.x11.clipboardString)
-            break;
-    }
-
-    if (_glfw.x11.clipboardString == NULL)
-    {
-        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
-                        "X11: Failed to convert clipboard to string");
-    }
-
-    return _glfw.x11.clipboardString;
+    return getSelection(_glfw.x11.CLIPBOARD, &_glfw.x11.clipboardString);
 }
 
 void _glfwPlatformGetRequiredInstanceExtensions(char** extensions)
@@ -2807,3 +2823,28 @@ GLFWAPI Window glfwGetX11Window(GLFWwindow* handle)
     return window->x11.handle;
 }
 
+GLFWAPI void glfwSetX11SelectionString(const char* string)
+{
+    _GLFW_REQUIRE_INIT();
+
+    free(_glfw.x11.primarySelectionString);
+    _glfw.x11.primarySelectionString = strdup(string);
+
+    XSetSelectionOwner(_glfw.x11.display,
+                       _glfw.x11.PRIMARY,
+                       _glfw.x11.helperWindowHandle,
+                       CurrentTime);
+
+    if (XGetSelectionOwner(_glfw.x11.display, _glfw.x11.PRIMARY) !=
+        _glfw.x11.helperWindowHandle)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "X11: Failed to become owner of primary selection");
+    }
+}
+
+GLFWAPI const char* glfwGetX11SelectionString(void)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+    return getSelection(_glfw.x11.PRIMARY, &_glfw.x11.primarySelectionString);
+}