Gordon Tennyson is the middle brother of Vera Tennyson and Max Tennyson and the father of Joel Tennyson. Unlike Max's side of the family, he, his wife Betty Jean Tennyson, and their son, are all members of the Plumbers.
He has gray hair, a gray mustache, and black eyes.
In Big Fat Alien Wedding, his son Joel marries a Lenopan named Camille, putting an end to a long feud between the Lenopans and the Plumbers. Both Gordon and his wife were against the wedding at first (due to Camille being a Lenopan), but later realize they had treated her unfairly and apologize, accepting her into the family.
- Big Fat Alien Wedding (first appearance)