One of many NHL defenseman who were groomed as juniors by Kelowna of the Western Hockey League, Schenn was a Second All-Star Team selection in 2007-08 and played in the CHL Top Prospects game.

Schenn was selected by the Toronto Maple Leafs with the No. 5 pick in the 2008 NHL Draft and made his NHL debut Oct. 9, 2008, against the Detroit Red Wings. He recorded his first NHL point with an assist Oct. 29, 2008, against the New Jersey Devils, and scored his first NHL goal Feb. 7, 2009, against the Montreal Canadiens.

He was picked to play in the Young Stars Game at the NHL All-Star Game during the 2008-09 season. Collecting two goals and 14 points in 70 games, Schenn was selected to the NHL All-Rookie team.

Appearing in 79 games with the Leafs in 2009-10, Schenn led the team in hits (173) and was second in blocked shots (116). He scored five goals in 2009-10 and 2010-11, and topped the 20-point plateau in 2010-11 and 2011-12. Schenn led all NHL defensemen with 251 hits in 2010-11 and was first on the Leafs with 168 blocked shots.

On June 23, 2012, the Leafs traded Schenn to the Philadelphia Flyers. The move reunited Schenn with his younger brother, Flyers forward Brayden Schenn.

Schenn finished the 2012-13 season with 187 hits, tied for third in the NHL. Schenn played 32:51 for the Flyers in an April 15, 2012 game at Montreal, the most minutes a Philadelphia player had skated in a game since Eric Desjardins played 33:14 on Feb. 27, 2001.

Schenn played his 400th NHL game Jan 12, 2014, against the New York Rangers. He finished the 2013-14 campaign with 260 hits to lead the Flyers and finish sixth in the NHL. On Oct. 18, 2014, against the Dallas Stars, Luke assisted on a goal by Brayden, the first time the two brothers had ever combined for a goal in the NHL. They reversed roles Nov. 4, 2014, against the Edmonton Oilers, when Brayden setting up a goal for Luke, which was Luke's 100th NHL point.

On Jan. 6, 2016, the Flyers traded Schenn to the Los Angeles Kings. On July 23, 2016, Schenn signed a free agent contract with the Arizona Coyotes.

Schenn won a gold medal with Canada at the 2008 World Junior Championship and a silver medal at the 2009 World Championship.

NOTES & TRANSACTIONS

• WHL West Second All-Star Team (2008)
• NHL All-Rookie Team (2009)
• Traded to Philadelphia by Toronto for James van Riemsdyk, June 23, 2012.
• Traded to Los Angeles by Philadelphia with Vincent Lecavalier for Jordan Weal and Los Angeles' 3rd round pick (Carsen Twarynski) in 2016 NHL Draft, January 6, 2016.
• Signed as a free agent by Arizona, July 23, 2016.
• Signed as a free agent by Anaheim, July 2, 2018.
• Traded to Vancouver by Anaheim with Vancouver's 7th-round pick in 2020 NHL Draft for Michael Del Zotto, January 17, 2019.
• Signed as a free agent by Tampa Bay, July 1, 2019.