Mario Ančić (born March 30, 1984) is a professional tennis player from Croatia. He is sometimes nicknamed "Super Mario" or "Baby Goran."

As a teenager making his Grand Slam debut at Wimbledon in 2002, he defeated 9th-seeded Roger Federer, becoming the first teenager since Björn Borg to win his Wimbledon debut on Centre Court. The win also makes him the last player to defeat Federer at the All England Club, and Grass courts.

Ančić and Ivan Ljubičić became the only doubles team to ever defeat Bob and Mike Bryan in Davis Cup history. Ančić helped Croatia win the 2005 Davis Cup, where they triumphed over the Slovakian Davis Cup team in the final.