M61

M61 or M-61 may refer to:

In transportation:
 * M61 motorway, a motorway in England
 * M-61 (Michigan highway), a state highway in Michigan
 * M61, a class of locomotives built by NOHAB

In science:
 * Messier 61 (M61), a spiral galaxy in the Virgo Cluster

In firearms and military equipment:
 * M61 Vulcan, a rotary cannon developed for the United States Armed Forces and used in fighter aircraft and other applications
 * M61 (grenade), a fragmentation hand grenade used by the United States Armed Forces
 * M61 Skorpion, a Yugoslav designation for the CZ-Scorpion pistol
 * M61 gas mask, a gas mask used by the Finnish Defence Forces of which three variants were made