Efe Üstündağ (born 15 January 1977) is a Turkish former professional tennis player.

He was a member of the Turkey Davis Cup team from 1998 to 2001 and won two ITF Futures doubles titles.

[1] Üstündağ, a native of Istanbul, has been Rice University men's head coach since 2012.

[2] A former Rice University player, Üstündağ twice earned All-American honors.

In 1999 he and Shane Stone were NCAA doubles quarter-finalists.