Eleventh Army or 11th Army may refer to:
Germany 11th Army (German Empire), a World War I field Army 11th Army (Wehrmacht), a World War II field army 11th SS Panzer Army
Russia 11th Army (Russian Empire) 11th Army (RSFSR) 11th Army (Soviet Union) 11th Air Army (Russia)
Others Eleventh Army (Japan) Eleventh Army (Italy) Eleventh Army (Austria-Hungary) 11th Army Group (United Kingdom)