diff --git a/code/__DEFINES/keybinding.dm b/code/__DEFINES/keybinding.dm
index 97b9c9d82aad..50a16edc350a 100644
--- a/code/__DEFINES/keybinding.dm
+++ b/code/__DEFINES/keybinding.dm
@@ -31,6 +31,7 @@
 #define COMSIG_KB_CLIENT_GETHELP_DOWN "keybinding_client_gethelp_down"
 #define COMSIG_KB_CLIENT_SCREENSHOT_DOWN "keybinding_client_screenshot_down"
 #define COMSIG_KB_CLIENT_MINIMALHUD_DOWN "keybinding_client_minimalhud_down"
+#define COMSIG_KB_CLIENT_FULLSCREEN_DOWN "keybinding_client_fullscreen_down"
 
 //Communication
 #define COMSIG_KB_CLIENT_OOC_DOWN "keybinding_client_ooc_down"
diff --git a/code/datums/keybinding/client.dm b/code/datums/keybinding/client.dm
index e4b940c7f722..3e78c4ac4c23 100644
--- a/code/datums/keybinding/client.dm
+++ b/code/datums/keybinding/client.dm
@@ -45,3 +45,39 @@
 		return
 	user.mob.button_pressed_F12()
 	return TRUE
+
+/client
+	var/fullscreen = FALSE
+/datum/keybinding/client/t_fullscreen
+	hotkey_keys = list("F11")
+	name = "change_fullscreen"
+	full_name = "Toggle Fullscreen"
+	description = "Change window to Fullscreen or back"
+	keybind_signal = COMSIG_KB_CLIENT_FULLSCREEN_DOWN
+
+/datum/keybinding/client/t_fullscreen/down(client/C)
+	. = ..()
+	C.toggle_fullscreen()
+
+
+/client/verb/toggle_fullscreen()
+	set name = "Toggle Fullscreen"
+	set category = "OOC"
+
+	fullscreen = !fullscreen
+
+	if (fullscreen)
+		winset(usr, "mainwindow", "on-size=")
+		winset(usr, "mainwindow", "titlebar=false")
+		winset(usr, "mainwindow", "can-resize=false")
+		winset(usr, "mainwindow", "menu=")
+		winset(usr, "mainwindow", "is-maximized=false")
+		winset(usr, "mainwindow", "is-maximized=true")
+	else
+		winset(usr, "mainwindow", "titlebar=true")
+		winset(usr, "mainwindow", "can-resize=true")
+		winset(usr, "mainwindow", "menu=menu")
+		winset(usr, "mainwindow", "is-maximized=false")
+		winset(usr, "mainwindow", "on-size=fitviewport")
+
+	fit_viewport()