The following units of the German First Army and British Expeditionary Force fought in the Battle of Mons in World War I.
German First Army
First Army, commanded by Generaloberst Alexander von Kluck
II Army Corps
30th Aviation Battalion
15th Foot Artillery Regiment (heavy)
3rd Infantry Division
3rd Artillery Brigade
3rd Horse Grenadiers
5th Infantry Brigade
2nd Grenadier Regiment
9th Grenadier Regiment
6th Infantry Brigade
34th Fusilier Regiment
42nd Infantry Regiment
4th Infantry Division
4th Artillery Brigade
12th Dragoons
7th Infantry Brigade
14th Infantry Regiment
149th Infantry Regiment
8th Infantry Brigade
49th Infantry Regiment
140th Infantry Regiment
III Army Corps
7th Aviation Battalion
2nd Guard Foot Artillery (heavy) 3rd Hussars
5th Infantry Division
5th Artillery Brigade
9th Infantry Brigade
8th Leib Grenadier Regiment
48th Infantry Regiment
10th Infantry Brigade
12th Grenadier Regiment
52nd Infantry Regiment
6th Infantry Division
6th Artillery Brigade
11th Infantry Brigade
20th Infantry Regiment
35th Fusilier Regiment
12th Infantry Brigade
24th Infantry Regiment
64th Infantry Regiment
3rd Jaeger Battalion
IV Army Corps
9th Aviation Battalion
4th Foot Artillery Regiment (heavy) 10th Hussars
7th Infantry Division
7th Artillery Brigade
13th Infantry Brigade
26th Infantry Regiment
66th Infantry Regiment
14th Infantry Brigade
27th Infantry Regiment
165th Infantry Regiment
8th Infantry Division
8th Artillery Brigade
15th Infantry Brigade
36th Fusilier Regiment
93rd Infantry Regiment
16th Infantry Brigade
72nd Infantry Regiment
153rd Infantry Regiment
4th Jaeger Battalion
IX Army Corps
9th Aviation Battalion
20th Foot Artillery Regiment (heavy) 16th Dragoons
17th Infantry Division
17th Artillery Brigade
33rd Infantry Brigade
75th Infantry Regiment
76th Infantry Regiment
34th Infantry Brigade
89th Grenadier Regiment
90th Fusilier Regiment
9th Jaeger Battalion
18th Infantry Division
18th Artillery Brigade
35th Infantry Brigade
84th Infantry Regiment
86th Fusilier Regiment
36th Infantry Brigade
31st Infantry Regiment
85th Infantry Regiment
III Reserve Corps
5th Reserve Division
2nd Reserve Dragoon Regiment (3 squadrons) 6th Reserve Field Artillery Regiment (6 batteries)
9th Reserve Infantry Brigade
8th Reserve Infantry Regiment
48th Reserve Infantry Regiment
10th Reserve Infantry Brigade
12th Reserve Infantry Regiment
52nd Reserve Infantry Regiment
6th Reserve Division
3rd Reserve Uhlan Regiment (3 squadrons) 6th Reserve Field Artillery Regiment (6 batteries)
11th Reserve Infantry Brigade
20th Reserve Infantry Regiment
24th Reserve Infantry Regiment
12th Reserve Infantry Brigade
26th Reserve Infantry Regiment
35th Reserve Infantry Regiment
IV Reserve Corps
7th Reserve Division
1st Reserve Schwere Reiter Regiment (3 squadrons) 7th Field Artillery Regiment (6 batteries)
13th Reserve Brigade
27th Reserve Infantry Regiment
36th Reserve Infantry Regiment
14th Reserve Brigade
66th Reserve Infantry Regiment
72nd Reserve Infantry Regiment
4th Reserve Jaeger Battalion
22nd Reserve Division
1st Reserve Jäger zu Pferde Regiment (3 squadrons) 22nd Reserve Field Artillery Regiment (6 batteries)
43rd Reserve Infantry Brigade
71st Reserve Infantry Regiment
94th Reserve Infantry Regiment
11th Reserve Jaeger Battalion
44th Reserve Infantry Brigade
32nd Reserve Infantry Regiment
82nd Reserve Infantry Regiment
10th Mixed Landwehr Brigade
12th Landwehr Infantry Regiment
52nd Landwehr Infantry Regiment
11th Mixed Landwehr Brigade
20th Landwehr Infantry Regiment
35th Landwehr Infantry Regiment
27th Landwehr Brigade
53rd Landwehr Infantry Regiment
55th Landwehr Infantry Regiment
Composite Landwehr Cavalry Unit (3 squadrons) Composite Lansturm Artillery Unit (2 batteries)