M41, M-41, or M.41 may refer to:

Transportation

• M-41 (Michigan highway), a former state highway in Michigan
• M41 (Cape Town), a Metropolitan Route in Cape Town, South Africa
• M41 (Johannesburg), a Metropolitan Route in Johannesburg, South Africa
• M41 (Durban), a Metropolitan Route near Durban, South Africa
• M41 motorway, a En motorway in England
• M41 highway, a major highway in Central Asia which crosses the Pamir Mountains
• BMW M41, a 1994 straight-4 diesel engine

Military

• M41 Walker Bulldog, an American light tank
• M41 155 mm Howitzer Motor Carriage, developed from M24 Chaffee
• M1941 Johnson rifle
• M1941 Johnson Light Machine Gun
• Macchi M.41 and M.41bis, an Italian flying boat fighter of the 1930s
• Type 41 75 mm Mountain Gun, a Japanese artillery gun
• HMS Quorn (M41), a British naval minesweeper
• M41 Light Rifle/TLR-41, a possible designation for the Thompson Light Rifle
• M-1941 Field Jacket, a World War II-era US Army uniform jacket

Entertainment

• M41A pulse rifle, a fictional assault rifle from the 1986 film Aliens and related media
• The 41st millennium, as expressed in the game Warhammer 40000.

Other

• Messier 41 (M41), an open star cluster in the constellation Canis Major
• M41, a postcode in the M postcode area that covers the town of Urmston, United Kingdom
• the 41st Mersenne prime