Richard John Brennan (born November 26, 1972) is an American retired professional ice hockey defenceman.

He played briefly in the NHL with a number of teams including the Colorado Avalanche, San Jose Sharks, New York Rangers, Los Angeles Kings, Nashville Predators, and Boston Bruins.

Brennan spent the 1996–97 season with the Hershey Bears in addition to making his NHL debut, appearing in 2 games with the Colorado Avalanche.

He split one year between Swiss team SC Bern of the NLA before transferring to Augsburger Panther of the DEL in Germany.

Brennan then spent the 2008–09 season in the Austrian Hockey League with HC TWK Innsbruck before retiring.