Following this, Cahill lost in the first round of five ranking events, including the UK Championship and Welsh Open. He did, however, defeat Robbie Williams and Noppon Saengkham before losing to Ken Doherty in the third round of the non-ranking one-frame Snooker Shoot-Out event. He finished the season losing in the opening round of qualification for the 2017 World Snooker Championship, losing to Robbie Williams 1–10. Having finished the season with a world ranking of 106, Cahill required a successful run in Q School at the end of the season to remain on the tour. After exiting in the opening round Andres Petrov 2–4 of the first event, He fared better at the second event, defeating Jaspal Bamotra, James Silverwood, Alex Taubman, Ashley Carty but lost 2–4 to Paul Davison to confirm his relegation from the tour.