When A = k[x 1 , . . . , xn] and G is a small subgroup of GLn(k), Auslander's Theorem says that the skew group algebra A#G is isomorphic to End A G (A) as graded algebras. We prove a generalization of Auslander's Theorem for permutation actions on (−1)-skew polynomial rings, (−1)-quantum Weyl algebras, three-dimensional Sklyanin algebras, and a certain homogeneous down-up algebra. We also show that certain fixed rings A G are graded isolated singularities in the sense of Ueyama.