The Thompson Okanagan Senior Lacrosse League (TOSLL) is a men's Senior C amateur box lacrosse league sanctioned by the British Columbia Lacrosse Association in Canada.

Originally formed in 1994 as the Interior Senior Lacrosse League, the name changed after 1999 to Thompson Xtreme Lacrosse League.

Before the 2012 season the league again renamed to the current TOSLL.