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.

Lassen has collaborated with African musicians and dancers from Kenya, Tanzania, Ethiopia, Mozambique, and Uganda.

He later relocated to Zanzibar in 2013 for a three-month stay in order to teach and start a jazz program at Dhow Countries Music Academy for young musicians.

Lassen has also worked with the following people: Rob Waring, Mathias Eick, Ray Phiri, Mohamed Issa Matona, LABtrio, Corrie Dick, Arthur Kay, Tord Gustavsen, Morten Qvenild, Emilie Stoesen Christensen, Anja Lauvdal, and Bram De Looze.