Ann-Mari Katharine Thomassen (born 1964) is a Sámi politician and a schoolteacher.

She completed her education as a teacher at the University of Tromsø (1995), specializing in Sámi (1996).

In 1989, she became a committee member of the Sámi association Inna ja Biras, serving as its leader from 1992 to 1994.

[2] She also serves on a number of other boards and committees, including the Sandstrand School Choir, Stuornjárgga Sámiid Duodji, the Santor sports association and the Bygdeutviklingsselskap building development company.

[4] Thomassen lives with her partner Sten Jakob Olsen.