Gilbert was eliminated in the qualifying rounds of the opening two ranking events of the season.&lt;ref name="2015/16"&gt;&lt;/ref&gt; At the minor-ranking Ruhr Open he won four matches to play in the quarter-finals where he beat Barry Hawkins 4–2, before losing 4–3 to Tian Pengfei in the semis. Gilbert's form continued later in to the month at the International Championship as he knocked out Xiao Guodong 6–5, Oliver Lines 6–4 and Ryan Day 6–4 to play in the first ranking event quarter-final of his career. He came back from 4–2 down against Marco Fu to edge it 6–5 which included a 130 break and then saw off Thepchaiya Un-Nooh 9–5. In the final, Gilbert was level with John Higgins at 4–4, but would lose 9–5. The £65,000 runner-up's cheque is by far the biggest of his career and he moved up to 21st in the world rankings afterwards. Gilbert stated that his newfound form was down to a new cue he acquired from fellow professional Matthew Selt six weeks previously. Gilbert was knocked out in the third round of both the UK Championship and China Open 6–3 to Marco Fu and 5–3 to Higgins respectively. Gilbert won three matches to qualify for the World Championship and faced Ronnie O'Sullivan in the first round. He was defeated 10–7, but said it was the best he had ever played without winning a match. He moved up to world number 22 at the end of the season.