PSL may also refer to:
In mathematics, the projective special linear group PSL(2, 7) (isomorphic to GL(3, 2)) is a finite simple group that has important applications in algebra, geometry, and number theory. It is the automorphism group of the Klein quartic as well as the symmetry group of the Fano plane. With 168 elements PSL(2, 7) is the second-smallest nonabelian simple group after the alternating group A on five letters with 60 elements (the rotational icosahedral symmetry group), or the isomorphic PSL(2, 5).
The PSL (, "scoped semi-automatic rifle") is a Romanian military designated marksman rifle. It is also called PSL-54C, Romak III, FPK and SSG-97 (Scharfschützengewehr - 1997). Though similar in appearance to the SVD Dragunov, the PSL rifle is actually based on the RPK light machine gun.