Backstrom may not have the name recognition as longtime linemate Alex Ovechkin, but his performance on the ice puts him in some elite company. Since joining the Capitals for the 2007-08 season, Backstrom has been one of the NHL's most consistent scorers and playmakers, and he played a key role in Washington's run to the Stanley Cup in 2018 with 23 points (five goals, 18 assists) in 20 games.

Backstrom's skills were apparent as early as the 2006 IIHF World Championship. At the age of 18 years and six months, he became the youngest player to represent Sweden; Backstrom appeared in four games and helped win the gold medal.

That same season, he was named the Swedish Elite League Rookie of the Year after finishing with 26 points (10 goals, 16 assists) for Brynas while also being selected as the top junior player in Sweden. Eight years later, he won a silver medal with Sweden at the 2014 Sochi Olympics.

Backstrom was chosen by Washington in the first round (No. 4) of the 2006 NHL Draft, with Ovechkin announcing the pick. After one more season at Brynas, Backstrom set a Capitals rookie record in 2007-08 with 55 assists. He also became the first rookie in NHL history to have consecutive games with at least four assists (Jan. 19-21, 2008). He scored goals in four consecutive games in Washington's opening-round Stanley Cup Playoff series against the Philadelphia Flyers, which the Capitals lost in seven games.

Backstrom finished second to Patrick Kane of the Chicago Blackhawks for the Calder Trophy and he was selected to the NHL All-Rookie team.

Two years later, he had NHL career highs of 33 goals, 68 assists and 101 points.

Backstrom's patient playmaking ability and offensive instincts, combined with a smart, sound defensive game, have made the 6-foot-1, 210-pound center one of the most consistent players in the League. He had at least 50 assists and 70 points from 2013-14 through 2018-19.

On March 15, 2015, Backstrom became the all-time assist leader in Capitals history and finished the season with 60, tops in the NHL. He scored his 200th NHL goal on Feb. 6, 2018, against the Columbus Blue Jackets, and reached the 900-point mark during a one-goal, three-assist game against the New Jersey Devils on Dec. 20, 2019. His 23 points (five goals, 18 assists) in the 2018 playoffs helped the Capitals win the Stanley Cup for the first time in their history.

Backstrom got his 1,000th NHL point at the Edmonton Oilers on March 9, 2022, joining Ovechkin as the second player in Capitals history to reach the milestone and the 40th in NHL history to do it with one team. He had one assist in eight games to start the 2023-24 season before taking time away from hockey because of what he called "my ongoing injury situation."

Backstrom returned to his native Sweden to resume his hockey career when he signed a contract with Brynas on July 28, 2025.