Webster saw off Ron Meulenkamp 3–1 in the first round of the 2015 World Championship and then missed one dart to level at 1–1 in the next round against Phil Taylor, going on to be whitewashed 4–0. He just hung on to his top 32 ranking after the event as he was the world number 32. At the first UK Open Qualifier of the year, Webster reached his first semi-final in an individual event for three years where he was edged out 6–5 by Michael van Gerwen. The result helped him enter the UK Open at the third round stage but he was beaten 9–5 by William O'Connor. Webster played with Jamie Lewis at the World Cup for the first time and they suffered a surprise 5–3 loss to Hong Kong in the opening round.