The first ranking event Williams could reach in the 2015–16 season was the International Championship and he was beaten 6–5 by Ben Woollaston in the first round. At the UK Championship he overcame both Mitchell Mann and Joe Perry 6–3 and described the latter as the best win of his career, with Perry stating that his opponent's style and speed of play was a joke. Williams went on to lose 6–3 against Matthew Selt in the third round. He reached the second round of the Welsh Open and was edged out 4–3 by Barry Hawkins.&lt;ref name="2015/16"&gt;&lt;/ref&gt; Williams qualified for the World Championship for the third year in a row by beating Gareth Allen 10–7, Mark Joyce 10–4 and Anthony Hamilton 10–9. Even though Williams said afterwards that he felt like the worst player in the tournament, he led Ricky Walden (a player who had lost in the final of the previous two ranking events) 5–4 and 7–5, but would ultimately lose 10–8.