Greg Marmalard is the president of Omega House and the secondary antagonist of the 1978 film National Lampoon's Animal House.

He is portrayed by James Daughton.

Like most of the Omegas, Greg is snobby and uptight. He is also against premarital sex and suffers from erectile dysfunction. After Otter, one of the rival Deltas, sleeps with his girlfriend, he and the rest of the Omegas beat Otter up. The Deltas are soon after expelled due to poor grades.

In "Where Are They Now?", it is revealed that Greg became a Nixon White House aide and after the Watergate scandal he was sent to prison, where he was raped.