Kempe first started skating when he was five years-old on an outdoor rink in his hometown of Kramfors. He represented Ångermanland twice in TV-pucken while playing for Modo Hockey's junior teams in Örnsköldsvik, Sweden. During the 2005–06 season, Kempe represented Team Sweden at the 2006 IIHF Under-18 World Championship. That following summer, Kempe was drafted 31st overall in the 2006 CHL Import Draft by the St. John's Fog Devils of the QMJHL. Kempe made the trip to North America and cracked the Fog Devils lineup. He was named an assistant captain during his rookie season. Kempe finished the season tied for 6th among QMJHL rookies in goals and 11th in points, and was voted "Fastest Skater in the Eastern Division". Kempe was ranked 50th among North American prospects on Central Scouting's final report heading into the 2007 NHL Entry Draft. He was chosen in the 5th round, 122nd overall by the Philadelphia Flyers. Kempe returned to his native Sweden after completing two seasons in the QMJHL. He signed with Rögle BK of Elitserien in the off-season and recorded two goals and eight assists in thirty games-played. After receiving limited ice time during the first half of the year he was traded to Mora IK of the second-highest level league in Sweden. He signed a two-year contract with Djurgården on 16 June 2010. Following the 2016–17 campaign and after three seasons in the Kontinental Hockey League with HC Vityaz, Kempe left as a free agent and returned to North America in securing a one-year, two-way contract with the Arizona Coyotes of the National Hockey League on 16 May 2017. On 28 May 2018, he signed a one-year contract extension with the Coyotes. On 5 July 2019, Kempe signed a one-year two-way contract with the Los Angeles Kings, joining brother Adrian. He was assigned to the Ontario Reign for the beginning of the 2019–20 season. Named as an alternate captain for the Reign, Kempe registered 3 goals and 11 points through 16 games in the AHL before he was placed on unconditional waivers by Kings in order for a mutual termination of his contract on 19 November 2019. As a free agent, Kempe returned for a second stint in Russia and the KHL, agreeing to a two-year contract with reigning Gagarin Cup champions CSKA Moscow on 21 November 2019.
International play
On 9 May 2019, Kempe was named to make his senior international debut with Sweden at the 2019 World Championships held in Bratislava, Slovakia.
Personal life
Kempe's younger brother, Adrian, is also a member of the Kings.
