At the 2016 Indian Open, Lines reached the last 16 of a ranking event for the first time by beating Graeme Dott 4–1 and Andrew Higginson 4–2, but lost 4–2 to Shaun Murphy. After defeating Martin O'Donnell at the UK Championship, Lines knocked out world number three Judd Trump 6–2 and said it was the first time he had played well in a televised match. He reached the last 16 for the second time this season by dispatching Jimmy Robertson 6–0, but could not pick up a frame himself as Marco Fu won 6–0. After losing 4–0 in the third round of the Scottish Open, Lines lost five of his six matches in the remainder of the season.