Ruben Enrique Douglas (born October 30, 1979) is a Panamanian-American professional basketball player. He is a 1.96 m (6 ft 5 in) 210 lb (95 kg) point guard-shooting guard.

Douglas played high school basketball at Bellarmine-Jefferson High School in Burbank, California. He is ranked as one of the most prolific high school scorers in California state history.

After high school, Douglas played college basketball at the University of Arizona with the Arizona Wildcats in the 1998–99 season. Douglas led the NCAA in scoring with a 28.0 points per game average during the 2002–03 season as a senior year at the University of New Mexico while playing with the New Mexico Lobos. He was also named the Mountain West Conference MVP.

After going undrafted by any NBA teams, Douglas took his game overseas. He has played for Panionios of the Greek league (2003–04), Virtus Roma and Fortitudo Bologna (2004–05) of the Italian league, the latter with whom he won the Italian national championship, as well as Dynamo Moscow of the Russian league (2005–06), and Valencia of the Spanish league (2006–09). In 2010, he returned to Panionios.^[1]

Douglas won the EuroCup championship in 2006 with Dynamo Moscow, and he was also named the EuroCup Finals MVP. Douglas last played with Uşak Üniversitesi Belediyespor, a Turkish team playing in the Turkish Second Division, starting in January 2012. He played against Tenis Eskrim Dağcılık in his first game with Uşak Belediyespor, on January 8, 2012.

Douglas was also a member of the senior men's Panama national basketball team that competed at the 2006 FIBA World Championship.