M11 or M-11 may refer to:
Aviation Miles M.11 Whitney Straight, a 1936 two-seater light aircraft Shvetsov M-11, an aircraft engine produced in the Soviet Union
Science Messier 11 (M11), an open star cluster also known as the Wild Duck Cluster Mathieu group M11 in the mathematical field of group theory Ritter M11 UltraClave, a model of autoclave made by Midmark
Transportation M-11, a state highway in the metropolitan area of Grand Rapids, Michigan M11 (East London), a Metropolitan Route in East London, South Africa M11 (Cape Town), a Metropolitan Route in Cape Town, South Africa M11 (Johannesburg), a Metropolitan Route in Johannesburg, South Africa M11 (Pretoria), a Metropolitan Route in Pretoria, South Africa M11 (Durban), a Metropolitan Route in Durban, South Africa M11 (Bloemfontein), a Metropolitan Route in Bloemfontein, South Africa M11 (Port Elizabeth), a Metropolitan Route in Port Elizabeth, South Africa M11 motorway in England M11 motorway (Pakistan) Sialkot - Lahore Motorway in Pakistan the Moscow–Saint Petersburg motorway, designated M11 Highway M11 (Ukraine) M11 motorway, portion of the N11 road in Ireland M11 (New South Wales), the NorthConnex motorway tunnel in Sydney, Australia Mornington Peninsula Freeway in Victoria, Australia designated M11 New York City Bus M11, a New York City Bus route in Manhattan M11 (Istanbul Metro), a rapid transit line of the Istanbul Metro M11 road (Zambia), a road in Zambia M11 road (Malawi), a road in Malawi Sri Lanka Railways M11, diesel-electric locomotives
Firearms and military equipment M11, a United States military designation for the SIG Sauer P228 semi-automatic pistol Ingram MAC-11, a sub-compact machine pistol M-11 Shtorm, a 1959 Russian naval surface-to-air missile system Fiat M11/39, an Italian medium tank used during World War II Grigorovich M-11, a 1916 Russian single-seat fighter flying boat Mk 11 Mod 0 Sniper Weapon System, a variant of the SR-25 used by the United States Navy Remington 11-87, a semi-automatic shotgun Panhard ULTRAV M11, a reconnaissance variant of the Véhicule Blindé Léger marketed to the US Army
Other M11, an abbreviation used to refer to the 11 March 2004 Madrid train bombings Change 2011, a Finnish political party which advocates direct democracy M-11 (comics), a fictional robot in Atlas Comics and Marvel Comics Magic 2011, the twelfth core set in Magic: The Gathering M11, a difficulty grade in mixed climbing M11, a postcode district for an area of east Manchester, see M postcode area