In the 2011–12 season, Dawson missed the opening game of the season, due to suffering from ankle injury, which he sustained in the club's pre-season tour. After returning, he made his first appearance of the season on 13 August 2011, in a 1–0 loss against Tranmere Rovers. However, after suffering another injury, Dawson continued to feature in the first team and wasn't until on 17 December 2011 when he scored, in a 2–1 win over Notts County. After the match, Dawson, along with teammate Scott Cuthbert, was named League One's Team of the Week for his display. In a 2–1 loss against Carlisle United on 7 January 2012, Dawson was substituted in the first half after a challenge from Jon-Paul McGovern, in what turns out to be his last appearance for Leyton Orient. After the match, it was announced that Dawson was sidelined for six weeks. By the time Dawson departed Leyton Orient, he made 24 appearances and scoring 2 times in all competitions.