- Played by Michael Gilday
Background
- Studied at the University of Michigan
- One of the founders of the Dharma Initiative
- Husband of Karen DeGroot
- Seen and mentioned in the Orientation film
Theories
- This could be Zeke, leader of The Others, however, Zeke/ Mr. Friendly is played by M.C. Gainey, Gerald DeGroot is not. It's unlikely that the producers of the show would have two actors playing one character
- Gerald DeGroot could have been a member of Geronimo Jackson