Harald Lassen (born March 13, 1987, in Kristiansand, Norway) is a Norwegian jazz musician, songwriter, and bandleader. In addition to being the front man of LASSEN, he has played with several other bands, including DUPLEX, Mopti (with Bendik Baksaas on the album Bits & Pieces), Pixel, and No. 4. Early on, he was drawn to the attention of musicians like drummer Jon Christensen and bassist Arild Andersen.
Harald Lassen grew up in Greipstad, Norway's Songdalen. He studied to become a saxophonist after spending many years as a pianist. Lassen studied from 2006 to 2007 at Toneheim Folkehøgskole and from 2007 to 2008 at the Institutt for Rytmisk Musikk at Universitetet i Agder. From 2008 to 2012, he undertook additional training at the Norwegian Academy of Music in jazz and improvised music.