Mehdi Addadi (Arabic: ???? ??????; born February 13, 1978) is an Algerian former swimmer, who specialized in sprint backstroke and butterfly events.
He collected two medals, a gold and a bronze, from the All-Africa Games, and later represented Algeria, along with Salim Iles, at the 2000 Summer Olympics.
While studying in the United States, Addadi was named 2001 Most Valuable Swimmer at the Eastern College Athletic Conference Championships, and 2002 Most Outstanding Swimmer by the University of Maryland, Baltimore County.
He also played for the University's swimming and diving team, under head coach Chad Cradock.