On September 18, 2013, Richardson was traded to the Indianapolis Colts for a 2014 first-round draft pick. The Colts were looking for a running back after a season-ending injury to Vick Ballard. In his first carry as a Colt, Richardson scored a one-yard touchdown against the San Francisco 49ers. He struggled through most of the season and was demoted in favor of Donald Brown on December 1, 2013. Richardson returned to his starting role in the Colts Week 15 game against the Houston Texans when Brown left due to injury, and recorded his first touchdown since Week 4 against Jacksonville. Richardson fumbled on his first career playoff carry against the Kansas City Chiefs in the Colts' Wild Card 45–44 victory.