A native of Edmonton, Foo began his junior hockey career in the Alberta Junior Hockey League, playing key offensive minutes and producing impressive offensive numbers in two seasons with the Bonnyville Pontiacs from 2012 to 2014. In his second season with the team, Foo scored 40 goals in 60 games, easily leading the team in scoring. Having aged out of eligibility to play in the AJHL and with little NHL interest, Foo moved on to play for the Union Dutchmen of the NCAA's ECAC Hockey conference beginning in the 2014–15 season. Foo posted pedestrian numbers in his first two seasons with the Dutchmen, scoring 25 points each year. However, the Calgary Flames' management was impressed enough by Foo's 2015–16 campaign to extend him an invite to their 2016 Fall Development Camp. He was not offered a contract. Foo broke out enormously in the 2016–17 season, scoring 62 points in 38 games, leading the Dutchmen in assists with 36 and finishing second in goals and points behind Mike Vecchione. This performance earned Foo significant NHL interest, with the Philadelphia Flyers, Detroit Red Wings, Vegas Golden Knights, and his hometown Edmonton Oilers reportedly all interest in signing him to an NHL contract. However, Foo ultimately committed to the Flames on 27 June 2017 and signed a two-year entry-level deal with the club on 1 July. Foo was assigned by the Flames to the American Hockey League's Stockton Heat on 26 September 2017 as part of a round of cuts during training camp. Foo started out slowly with the Heat, recording just 6 goals and 13 points in his first 30 games with the club. However, as the calendar flipped to 2018, he started heating up, scoring another 6 goals and adding 5 more assists in his next 9 games–earning him a nod as the AHL's Player of the Week for the week ending 28 January 2018. Foo played his first NHL game with the Calgary Flames against his hometown team, the Edmonton Oilers, in Calgary on March 31, 2018. He recorded his first career NHL goal on April 5, 2018, in a 2–1 loss to the Winnipeg Jets. On June 25, 2019, having completed his entry-level contract, Foo was tendered a qualifying offer with the Flames, retaining his rights. The following day, Foo of Chinese origin, was announced to have signed a two-year contract with Chinese club, Kunlun Red Star of the KHL.
