Mari Elina Knihtilä (born June 6, 1971) is a Finnish actress.

Knihtilä has worked for several Finnish theatres, such as the Finnish National Theatre and Q-teatteri, while also having appeared in films and on television. She has received two Jussi Awards; one for a supporting role in the 2008 Heikki Kujanpää film Putoavia enkeleitä and another for a leading role in the 2011 Zaida Bergroth film Hyvä poika. Some of her television work include the comic roles in Läpiveto, Vedetään hatusta and the first season of Putous.