Infobox last updated on: May 11, 2009.

Ivo Karlović (born February 28, 1979 in Zagreb, SR Croatia, Yugoslavia) is a Croatian tennis player. He has won four ATP singles titles: three in 2007 and one in 2008. He has also defeated several highly ranked opponents including Roger Federer (who was ranked No. 1 at the time), Lleyton Hewitt, Novak Djokovic, Andy Roddick, Fernando González, and James Blake.

He is the tallest player ever on the ATP Tour at 208 cm (6 ft 10 in). Although born in Zagreb, his surname Karlović reflects descent from the Zadar region of Dalmatia, along Croatia's coastline, which in turn forms a part of the Dinaric Alps which have the tallest average male height in Europe.