[19] Arriving at the age of four, Lewis grew up in Montreal, Quebec,[19] and pursued table tennis, golf, and weight–lifting.

[20] Karen, who won both singles and doubles tennis championships in her native city,[20] moved to Canada in her 20s to continue her studies.

[21] At the age of five, Chan showed talent in downhill skiing but focused on other sports after his family moved to Toronto.

[37] His coach, Osborne Colson, made him spend 30 minutes a day on basic stroking, edge work, cross-cutting, and balance drills.

He was assigned two Grand Prix events and made his senior international debut at the 2006 Trophée Éric Bompard, where he placed fifth.

[38] It was incorrectly reported that he had become the youngest Canadian men's champion in history—a record still held by Charles Snelling, who was 16 at the time of his 1954 victory.

[38] At his only appearance at the 2009 Four Continents Championships, Chan placed first in the short program, in which he received level 4 for all his spins and for his straight–line footwork.

During the off-season, Chan performed in the South Korean show Festa on Ice alongside Yuna Kim once again.

In July 2009, Chan landed a quad toe loop jump during a warm-up session at the 2009 Liberty Summer Competition.

Chan was assigned to the 2009 Rostelecom Cup and the 2009 Skate Canada International events for the 2009–10 ISU Grand Prix season.

[50] Chan's injury rehabilitation included a treatment in which his blood was drawn, spun and concentrated, and injected back into his injured muscle.

On January 8, 2010, Chan announced a coaching change to Lori Nichol, his long–time choreographer, and Christy Krall, a technical specialist based in Colorado.

[53][54] At the 2010 Canadian Championships, he placed first in the short program, 11.27 points ahead of Vaughn Chipeur, after making a mistake on a 3F and receiving level fours for all his spins and his two step sequences.

Chan began his season at the 2010 Liberty Summer Competition where he debuted his new short program to the music of Take Five, a jazz piece.

[74] Chan worked with Peter Davis, the former sports science director for the US Olympic Committee; choreographer Lori Nichol; Kathy Johnson, a movement and balance coach; Andy O'Brien, a strength, fitness, and nutrition coach; physiotherapist Mark Lindsay; and Eddie Shipstead who helped with quads, using special harnesses which prevent injury.

Just before the Final, an interview was released that caused controversy; Chan and Skate Canada officials said that his comments had been misconstrued.

[24][80] Chan said that his parents had made sacrifices for his skating career and that he felt connected to his Chinese heritage due to the support he received from the Chinese–Canadian community.

He placed first in the short program, as well as in the free skate, to win the gold medal by an 11.18 point margin over Daisuke Takahashi.

He left his longtime choreographer Lori Nichol and asked Jeff Buttle and David Wilson to produce his competitive programs.

At the 2012 Skate Canada International he competed as the defending champion and obtained the silver medal, behind Spain's Javier Fernández.

At the 2013 World Championships, held in London, Ontario, Canada, Chan won the short program where he landed a 4T–3T combination, 3A, and 3Lz, and received level fours in his spins and footwork earning 6.81 points more than Denis Ten from Kazakhstan.

[94][95] During the summer of 2013, Chan moved his training base from Colorado to Detroit to continue to work with Kathy Johnson.

[113] On September 23, 2016, Chan announced that his new coaching team would be led by Marina Zueva, and his training base would be Canton, Michigan.

During the season, he attempted to incorporate a quadruple Salchow into his repertoire in response to the increasing jump difficulty of his top competitors.

During his final competitive season, Chan placed fourth at the 2017 Skate Canada International and withdrew from the 2017 NHK Trophy.

In the individual men's event, Chan finished ninth after placing sixth in the short program and eighth in the free skate.

[132] 1992 Olympic champion Viktor Petrenko also said: "You can see why Chan's PCS is so high by counting the number of crossovers he makes during his performance, which is a clear indication that his components are at the highest level.

[4] The ability to control speed on the ice allows Chan to accelerate and gain momentum in a short time to achieve the speed needed, so that he can perform quads in short approach, while a lot other athletes often have to slide a longer distance around the rink to gain momentum when performing quads.

[4][135] Since a young age, he has been appreciated for his smooth skating technique, large ice coverage, and ability to engage in acting in competition as well as the artistry of the programs.

Chan is thereby considered one of the pioneers of the modern era of men's figure skating with strong programs in both technique and artistry.