Ivo Karlović (born February 28, 1979) is a Croatian tennis player who burst onto the ATP circuit during the 2003 Wimbledon Championships, in which he grabbed his first Grand Slam victory after defeating the defending champion Lleyton Hewitt. At 208 cm (6'10"), Karlović is the tallest player to ever to play in an ATP event.

The 24 year old is from Zagreb, Croatia where he finished the 2003 year in the Top 100 and as the No. 3 Croat behind Ivan Ljubičić and Mario Ančić.

He is currently a member of the Croatian Davis Cup team. His debut was in 2000 against Ireland, when he won the dead rubber. Karlovic appeared in starting line-up for first time in 2002 against Argentina in Buenos Aires, but he lost to Juan Ignacio Chela in the second rubber and to Gaston Gaudio in fifth and decisive rubber. He has posted a 4-2 career record (2-2 in singles) in three ties since 2000.

Ivo continues to be a surprising force on the circuit during the 2004 season in which he won at Calabasas, California, and has made it to the round of sixteen in many tournaments, including Wimbledon, where he lost in straight sets to the future champion Roger Federer. In order to become a more dominant force, however, Karlović must improve his serve and volley as his baseline speed is compromised because of his large frame. His current ATP singles ranking, as of August 26, 2004, is 57th in the world.