MK3 may refer to:

Mortal Kombat 3, the third game in the Mortal Kombat series Mario Kart: Super Circuit, the third game in the Mario Kart series MAP kinase kinase kinase (MK3) MAPK-activated protein kinase 3 (MK3) Mark III (disambiguation) and Mark 3

See also

MKKK (disambiguation) M3K (disambiguation) MK (disambiguation)