Eelco Jansen (born 14 May 1969) is a Dutch former baseball player. He represented the Netherlands in the 1996, 2000, and 2004 Summer Olympics. He is the second pitcher in the history of Dutch baseball to achieve a perfect game.
Jansen represented the Netherlands at the 1996 Summer Olympics in Atlanta where he and his team became fifth. Four years later at the 2000 Summer Olympics in Sydney they were fifth again, while in Athens at the 2004 Summer Olympics they finished in sixth place.