Allen's only ranking event quarter-final this season came at his home event the Northern Ireland Open, but he lost 5–2 to Anthony Hamilton. He made the first 147 of his career during his 6–4 win over Rod Lawler in the second round of the UK Championship and then recovered from 4–0 down to eliminate Ryan Day 6–5. Allen was knocked out 6–3 by John Higgins in the fourth round, losing the final four frames of the match. He exacted some revenge by edging out Higgins 6–5 in the opening round of the Masters, before being defeated 6–2 by Marco Fu. He met Higgins again in the second round of the World Championship and, though Allen made four centuries and seven other breaks above 50, he was beaten 13–9.