Per Mathisen (born 7 October 1969) is a Norwegian jazz bassist and composer who has worked with Terri Lyne Carrington, Geri Allen, Gary Thomas, Bill Bruford, Alex Acuña, Gary Husband, Ralph Peterson, Nguyen Le and Terje Rypdal.

Mathisen was educated on the Jazz program at Trondheim musikkonservatorium 1991–93, followed by a period at the Berklee School of Music in US, and returned to Norway in 1994.

He played in various bands in the Oslo region, e.g. "Erlend Gjerde Quintet", "Inge Stangvik Quartet" and "Storeslem", and the records Her point of view (1997), Northern crossings (2000) and Some things from home (2001), as well as Unbound (2002/2006), with Olga Konkova.

From 2003 he was member of the transatlantic jazz collective NYNDK (with a release in 2006), so-called because the musicians come from New York, Norway and Denmark.

Mathisen has otherwise participated on recordings with the band "String Zone" (Mystery bag, 2003), Hans Mathisen (Quiet songs 2002–04), Helge Sunde & Norske Store Orkester (Denada, 2005) and Roy Powell Peak Experience Trio (2006), and has been a regular feature as bassist and leader of "workshops" in Groove Valley (annually held in Beiarn Municipality in Nordland) where artistic director is Jan Gunnar Hoff.