M13, M-13 or M₁₃ may refer to:

Military

* Fiat M13/40, an Italian tank used in World War II * M13 Half-track, a U.S. anti-aircraft gun used in World War II * M13 link, a machine gun's ammunition link * M-13 rocket, a version of the Soviet World War II RS-82 rocket * M13 revolver, a lightweight version of the Smith & Wesson Model 12 pistol for U.S. Air Force crew

Roads

* Highway M13 (Ukraine), an international highway connecting Ukraine and Moldova * M-13 (Michigan highway), a state highway in the United States * M13 (East London), a Metropolitan Route in East London, South Africa * M13 (Cape Town), a Metropolitan Route in Cape Town, South Africa * M13 (Johannesburg), a Metropolitan Route in Johannesburg, South Africa * M13 (Pretoria), a Metropolitan Route in Pretoria, South Africa * M13 (Durban), a Metropolitan Route in Durban, South Africa * M13 (Bloemfontein), a Metropolitan Route in Bloemfontein, South Africa * M13 (Port Elizabeth), a Metropolitan Route in Port Elizabeth, South Africa *M13 Road (Zambia), a road in Zambia

Other uses

* M13 (Istanbul Metro), a rapid transit rail line in Istanbul Turkey * M₁₃, the Mathieu groupoid by John Horton Conway * M13 bacteriophage, a virus that infects bacteria * Magic 2013, the fourteenth core set in ''Magic: The Gathering'' * Messier 13, a globular cluster in the constellation Hercules * Miles M.13 Hobby, an airplane built by Miles Aircraft * Samsung Galaxy M13, an Android-based smartphone manufactured by Samsung Electronics {{Letter-NumberCombDisambig