On 21 July 2011, Moffat was traded to Houston Dynamo along with allocation money in exchange for Lovel Palmer, Mike Chabala, and an international roster spot. He made his Dynamo debut on 23 July, coming off the bench in a 3–0 loss to Chivas USA. He made his first start on 30 July, helping Houston to a 3–0 win over the Seattle Sounders. On 14 August, Moffat scored his first goal for the Dynamo to help Houston defeat Portland 2–1. The goal, a strike from 40 yards out into the top right corner, was named as the MLS Goal of the Week. After missing a game due to receiving two yellow cards on 17 August, Moffat started every remaining game of the regular season for the Dynamo. On 23 October, Moffat scored once and added an assist to help the Dynamo to a 3–1 win over the LA Galaxy in the final game of the regular season. The goal, which was named as the MLS Goal of the Week, saw Moffat intercept a pass in midfield, dribble for a few yards, and then smash the ball into the top right corner from over 40 yards out. Moffat helped the Dynamo finish the regular season strong and earn a 2 seed in the Eastern Conference. In the playoffs, Moffat played every minute as he helped the Dynamo reach MLS Cup 2011, where the Dynamo lose 1–0 to the LA Galaxy.