M23, M.23 or M-23 may refer to:
Military HMS M23, a Royal Navy M23 chemical mine, a US landmine March 23 Movement (M23), a rebel military group operating in the Democratic Republic of the Congo M23 rebellion (2012–2013) M23 campaign (2022–present) Sako M23, a Finnish family of assault and battle rifles
Roads M23 motorway, a motorway in England M-23 (Michigan highway), a highway designation formerly used in Michigan Highway M23 (Ukraine) M23 (Cape Town), a Metropolitan Route in Cape Town, South Africa M23 (Pretoria), a Metropolitan Route in Pretoria, South Africa Federal Highway (Australia), part of which is given the designation "M23"
Other uses M23 (New York City bus), a New York City Bus route in Manhattan BFW M.23, two-seater sports plane The Mathieu group M23 in the mathematical field of group theory m23 software distribution system, a Linux software distribution and management system McLaren M23, a race car Messier 23 (M23), an open star cluster in the constellation Sagittarius M23 derby, a football match between Brighton and Crystal Palace, England Samsung Galaxy M23 5G, an Android-based smartphone