Lucas Lynggaard Tønnesen (born 13 July 2000)^[1] is a Danish actor. He is best known for his roles in the Netflix series The Rain and Borgen – Power & Glory.^[2][3][4][5] In 2022, Tønnesen starred in the Netflix multilingual mystery-science fiction series 1899.

Lucas Lynggaard Tønnesen was born in Copenhagen, Denmark. He has a younger sister, who is an acrobat. At the age of nine, he enrolled in a singing school in Copenhagen, joining a choir and travelling the world.^[6] In the summer of 2012, his father sent a recording of him singing to an audition, which landed Tønnesen the leading role in a theatre play called Cirkus Summarum. Following this, Tønnesen expressed a deep interest in acting.^[6][7]

Tønnesen began his career in film in the Danish comedy Player.^[1] He went on to appear in the film The Keeper of Lost Causes.^[8]

In 2014, he made his way into television by playing a regular role in the Danish series Tidsrejsen.^[3] In 2015, he starred as Oliver in the short film I Stykker. He resumed his foray into acting in 2018, taking on the role of Rasmus Andersen in the first Netflix Danish series, The Rain at the age of sixteen.^[2] The series ran for three seasons, until 2020.^{[2][3][4][9][10]}

Tønnesen went on to star in multiple short films in subsequent years. In 2022, he took on a recurring role in a Netflix co-production series, Borgen – Power & Glory, as Magnus Nyborg Christensen.^[5][11] He later starred in the multilingual Netflix mystery-horror series 1899, created by Baran bo Odar and Jantje Friese.^[12][13][14]