Before the start of the World Championship Carter stated that his future in the game depended on his health, as his ten-year battle with Crohn's disease continued. Three weeks before the start of the event he began cutting out dairy and wheat from his diet. This looked to have an effect on the snooker table too as he raced into an 8–1 lead over Mark Davis in the opening session of the first round, before returning to close out the match 10–2. He played world number 2 Judd Trump in the second round and from 9–12 behind, produced a superb fightback to record the result of his season to take the match 13–12 and reach the quarter-finals. He defeated impressive debutant Jamie Jones 13–11 in the last eight to book a semi-final with Stephen Maguire. He won this match by a 17–12 scoreline to play in a repeat of the 2008 final against Ronnie O'Sullivan. He lost 11–18, meaning he has now not beaten O'Sullivan in any of their 12 ranking event matches. Despite reaching the final, Carter finished the season ranked world number 17, meaning he had dropped 11 places during the year.