The Cohomology Rings of Rank 3 Simple Groups are Cohen-Macaulay by Alejandro Adem and R. James Milgram KEYWORDS Finite Simple Groups, Cohomology of Groups DATE March 29, 1995 STATUS to appear in Annals Math Studies (Browder Volume) COMMENT Abstract In this paper we show that the mod 2 cohomology ring of any finite simple group of rank 3 or less (at the prime 2) must be Cohen-Macaulay.