Simmons played three years of college basketball for DePaul University before being selected in the second round (42nd pick overall) of the 2001 NBA Draft by the Seattle SuperSonics. Simmons draft rights were traded to the Washington Wizards for Predrag Drobnjak on June 27th, 2001. Bobby was traded by the Wizards on September 11th, 2002, shortly before the start of the 2002-03 NBA Season, to the Detroit Pistons with Hubert Davis and Richard Hamilton for Jerry Stackhouse, Brian Cardinal, and Ratko Varda. Simmons was released by the Pistons on September 24th less than two weeks later and signed the Wizards again on October 10th. Bobby Simmons signed a free agent contract with the Los Angeles Clippers on September 26th, 2003.
The 6'6", 228lb small forward had a breakout year during the 2004-05 NBA season with the Los Angeles Clippers in which he averaged a career-high 16.4 points per game. He was rewarded for his stellar play with the NBA Most Improved Player Award.
Simmons has averages of 10.4 points and 4.3 rebounds per game in 26.7 minutes per game for his career (as of February 28th, 2006).