Boyle first played competitive hockey as a junior with New Jersey of the Atlantic Junior Hockey League from 2007 through 2010 and played one game for Tri-City of the United States Hockey League during his Rockets tenure. He played 39 games as an 18-year-old for Westside of the British Columbia Hockey League, where he earned All-Rookie team honors.

Boyle played his freshman and sophomore seasons at the University of Massachusetts Amherst and was 16-17-6 in 41 games before he was cut prior to his junior season. He had to sit out 2013-14 to transfer to the University of Massachusetts Lowell, where he enjoyed a standout senior season in 2015-16 by going 24-10-5 with a 1.83 goals-against average, .934 save percentage and seven shutouts to earn Hockey East Goaltender of the Year and Hockey East Co-Player of the Year, alongside Thatcher Demko. Boyle's seven shutouts set a UMass-Lowell single-season record and he played 2,364 to break Dwayne Roloson's school record of 2,342 set in 1993-94.

Though Boyle went undrafted, he agreed to a one-year, entry-level contract with the Anaheim Ducks on March 31, 2016. He started his first professional season with Utah of the ECHL and was 9-6-1 in 16 games before being promoted to San Diego of the American Hockey League, where he was 19-5-4 with one shutout. He signed another one-year contract June 30, 2017 to remain with the Ducks organization and played a full season in San Diego in 2017-18.

A pending restricted free agent, Boyle signed a two-year, two-way contract with Anaheim on July 19, 2018 and was recalled to the NHL for the first time Nov. 18. Because of injuries Ducks goalies John Gibson and Ryan Miller, Boyle was recalled Feb. 9, 2019 to back up Chad Johnson and made his NHL debut in relief of Johnson that night with 19 saves on 21 shots in a 6-2 loss to the Philadelphia Flyers. He excelled in his first NHL start by making 35 saves in a 1-0 win against the Vancouver Canucks on Feb. 13, 2019.