The Calgary Hitmen selected Jones in the fourth round of the 2005 WHL Bantam Draft. He joined the Hitmen in 2006–07 and served as the backup to Dan Spence for two seasons. He was eligible for the 2008 NHL Entry Draft but went undrafted. Offered a try-out with the Los Angeles Kings, Jones impressed team scouts at Los Angeles' rookie camp, and following a strong showing at their main camp, the team signed him to a three-year contract before reassigning him back to the Hitmen. He emerged as Calgary's starting goaltender in 2008–09; his 45 wins for the Hitmen broke the team record of 39. He led the league in wins, tied for the lead in shutouts and finished third in goals against average. He backstopped the Hitmen to 12 consecutive wins in the playoffs, tying a league record, before the Hitmen lost the WHL championship series in six games to the Kelowna Rockets. Jones was invited to participate in the Canadian junior team's summer camp, and earned a spot on the team as the backup to Jake Allen for the 2010 World Junior Ice Hockey Championships. He started one preliminary round game against Slovakia, winning 8–2, and relieved Allen in the gold medal game against the Americans, though Canada lost the game in overtime and ended the tournament with the silver medal. With the Hitmen, Jones finished with a league-best GAA of 2.21 and was named a First Team All-Star in the Eastern Conference. In advance of his second consecutive appearance in the championship series, the league named him the winner of the Del Wilson Trophy as the WHL's top goaltender. During the season, he surpassed Spence's team record for career wins, and his 16 career shutouts are also a franchise record.
Professional
Los Angeles Kings
The Kings assigned Jones to their American Hockey League affiliate, the Manchester Monarchs to begin the 2010–11 season. He also played with the Ontario Reign of the ECHL for a time, but after posting a 16–3–0 record,.939 save percentage and 1.93 GAA in his first 22 games for the Monarchs, Jones was chosen to play in the 2011 AHL All-Star Game. He was on the roster of the Los Angeles Kings as a spare when they won their second Stanley Cup, but did not play. Jones finished fourth in the AHL with 27 wins in 2012–13 and was also among the league leaders in games played and shutouts. Jones began the 2013–14 season with Manchester, but was recalled by Los Angeles on November 13, 2013, after Jonathan Quick suffered an injury. As the backup for the Kings, he did not get into game action for three weeks. Jones made his NHL debut on December 3 and earned a 3–2 victory over the Anaheim Ducks. He stopped all nine shooters he faced in a shootout to secure his first NHL win. Jones won his second NHL start and made 16 saves to record his first NHL shutout four nights later against the New York Islanders. He shut out the Montreal Canadiens in his next game, making him the first Kings goaltender to do so, and the second Los Angeles rookie to record consecutive shutouts, matching Gerry Desjardins, who did it in 1968–69. Jones then found himself a full-time NHL goaltender for the first time after backup Ben Scrivens was traded to Edmonton, making Jones the team's primary backup to starter Quick.
On June 26, 2015, Jones, set to become a restricted free agent on July 1, was traded to the Boston Bruins, along with Colin Miller and a first-round pick in the 2015 NHL Entry Draft, in exchange for forward Milan Lucic. In turn, the Bruins traded Jones to the San Jose Sharks on June 30 in exchange for Sean Kuraly and a 2016 first-round pick. The Sharks signed him to a three-year contract worth $9 million. Having his first season as a starting goaltender, Jones had 65 games in 2015–16 with the Sharks, finishing with a 2.27 goal-against average,.918 save percentage, and the second most shutouts in the regular season with six, next to Chicago Blackhawks netminder Corey Crawford with seven. Jones then helped the Sharks reach their first Stanley Cup Finals, starting 24 playoff games and having shutouts in three of them. On July 1, 2017, Jones signed a six-year, $34.5 million contract extension.
