MK5 may refer to:
Mortal Kombat: Deadly Alliance, the fifth game in the Mortal Kombat series Mario Kart DS, the fifth game in the Mario Kart series, released in 2005 for the Nintendo DS MK5, an English postcode district British Rail Mark 5, a rolling stock designation in the United Kingdom British Rail Mark 5A, a similar development of rolling stock in the United Kingdom