M34 or M-34 may refer to:
Transportation M-34 (Michigan highway), a road in the United States of America M34 highway (Tajikistan), a road connecting Dushanbe and the Anzob Pass M34 (Cape Town), a Metropolitan Route in Cape Town, South Africa M34 (Johannesburg), a Metropolitan Route in Johannesburg, South Africa M34 (Pretoria), a Metropolitan Route in Pretoria, South Africa M34 (Durban), a Metropolitan Route in Durban, South Africa HızRay, also known as M34, planned metro line in Istanbul
Vehicles Mikulin M-34, the Soviet Union's first indigenous mass-produced liquid-cooled aircraft engine M34 2½ ton cargo truck, a variant of the United States Army M35 2½ ton cargo truck M34 (keelboat), a French sailboat design
Other uses M34 (New York City bus) SBS and M34A (New York City bus) SBS, two New York City Bus routes in Manhattan M34 grenade M34 cluster bomb Messier 34, an open cluster in the constellation Perseus Samsung Galaxy M34 5G, an Android-based smartphone