C37 or C-37 may refer to:

Vehicles Aircraft Caudron C.37, a French passenger biplane Cessna C-37, an American civil utility aircraft Gulfstream Aerospace C-37A, an American military VIP passenger jet based on the Gulfstream V Gulfstream Aerospace C-37B, an American military VIP passenger jet based on the Gulfstream G550 Lockheed C-37 Electra, an American military transport

Automobiles Dongfeng Sokon C37, a Chinese van Marshall C37, a British bus Sauber C37, a Swiss Formula One car

Ships Corsair 37, an American trimaran sailboat , a C-class submarine of the Royal Navy Catalina 37, a yacht produced by Catalina Yachts

Other uses C37 road (Namibia) Caldwell 37, an open cluster King's Gambit, a chess opening Route C37 (Massachusetts), a street in Boston SARS-CoV-2 Lambda variant, also known as lineage C.37