Lönn was born in Borlänge. He worked for one year as a school teacher before becoming a local authority worker and later a parliamentary assistant to SD representative Mats Nordberg. He is chairman of the Young Swedes SDU in Dalarna and is a member of the regional council of Borlänge.[2] In 2023, Lönn was appointed to the Riksdag following the death of Mats Nordberg. However, he was allocated to take Sara Gille's seat due to the latter being on maternity leave while Rasmus Giertz would take Nordberg's seat.[3][4]