Mark Howe is a former professional ice hockey defenseman and left winger who played sixteen seasons in the National Hockey League (NHL) following six seasons in the World Hockey Association (WHA). Son of hockey legend Gordie Howe, he was known as one of the best two-way NHL defensemen of the 1980s, being a three-time runner-up for the Norris Trophy and making the Stanley Cup finals three times as a player.

Howe started his professional career in the WHA, deciding to play alongside his brother, Marty and his father Gordie. Led by the Howes, the Houston Aeros won the 1974 and 1975 Avco Cups, awarded to the league champions of the WHA. Mark, playing left wing, was awarded the Lou Kaplan Trophy as Rookie of the Year and earned 2nd team All-Star status. Having dual citizenship, he represented his father's country in the 1974 Summit Series, where he was one of Team Canada's leading scorers.

When the NHL and WHA merged in 1979, the Boston Bruins, who held his NHL rights, attempted to reclaim Mark Howe in the expansion draft, however, the Whalers used a priority selection to retain him. Due to a gentlemen's agreement between the Whalers and the Red Wings, Detroit opted not to exercise their right to reclaim Gordie Howe; the Wings also opted not to reclaim Marty, whose rights they had previously acquired from Montreal. As a result, Mark, his father and his brother were able to play one more season together with the Whalers, this time in the NHL.

In 1982, he joined the Flyers and played a pivotal role in their success, displaying his prowess as a versatile and offensively skilled defenseman. The backbone of one of the NHL's best defensive teams of the mid-1980s, Howe was a finalist for the Norris Trophy three times, those being in 1982–83, 1985–86 and 1986–87 season. Howe had his best season during the 1985–86 season where he posted some of the best numbers ever by an NHL defenseman, in particular, leading the NHL with a remarkable +85 Plus/Minus rating and 7 shorthanded goals. He scored 24 goals, added 58 assists for 82 total points while being the lifeline out of the Flyers defensive zone with his outstanding skating and passing abilities.

After the 1991–92 season, the Flyers granted Howe free agency and he signed with the Detroit Red Wings, the team with which his father had starred. Howe would have one more appearance in the Stanley Cup finals, but his Red Wings were swept in 1995 by the New Jersey Devils. Upon his retirement as a player following the 1994–95 season, Howe remained in the Detroit organization working in the hockey operations department first as a video coach and then as a pro scout, earning Stanley Cup rings when the Wings captured championships in 1997, 1998, 2002, and 2008.

Howe was elected to Philadelphia Flyers Hall of Fame in 2001 and the United States Hockey Hall of Fame in 2003. In June 2011, it was announced that Howe had been elected to the Hockey Hall of Fame to which he was inducted on November 14, 2011, in the players category.  On March 6, 2012, the Philadelphia Flyers retired Mark Howe's #2 jersey in an on-ice ceremony at the Wells Fargo Center prior to a game with the Detroit Red Wings. Howe's number became only the fifth number to be retired by the Flyers in the club's then 44-season history. He currently serves the club as its Director of Pro Scouting being based just outside Philadelphia in Jackson, NJ, from which he primarily covers NHL and AHL teams located in the eastern United States.