[2] On 21 June 2019, Björnfot was the second player to be selected by the Los Angeles Kings in the 2019 NHL Entry Draft, taken in the first round with the 22nd overall pick, which the Kings acquired from the Toronto Maple Leafs in a trade that sent Jake Muzzin to Toronto.
[3] On 8 August 2020, approaching the second year of his entry-level contract he was loaned by Los Angeles to his Swedish club, Djurgårdens IF, to continue his development before the commencement of the delayed North American 2020–21 season due to the COVID-19 pandemic.
[4] On 3 January 2024, after playing just one game for the Kings over the first three months of the 2023–24 season, Björnfot was placed on waivers before being claimed by the Vegas Golden Knights one day later.
[6] After playing only two games with Vegas, Björnfot suffered an undisclosed injury, and was placed on injured reserve.
[7][8] Upon his return from IR, Björnfot was waived by Vegas, and subsequently claimed by the Florida Panthers on 8 March 2024.