Dr. Gilbert Alva Gilliam (born March 8, 1957, age 54) is a well known doctor in Bikini Bottom He is usually seen whenever someone gets sick or has an accident. He is almost always purple, except in the episode "Once Bitten", he is orange. He has appeared in many episodes. Most of the time, he usually treats the main character of a certain episode. Dr. Gill Gilliam works at the Bikini Bottom Hospital. There he has treated many patients, and because he has helped so many people, it is possible that he has his own big ward or office.
- Dr. Gill Gilliam might be an orange version of Dr. Forrest.
- Dr. Gill Gilliam might be related to Dr. Forrest in some way.
- In the Emergency Room Lego set Dr. Forrest is misnamed Dr. Gill Gilliam.
- Dr. Gill Gilliam and Dr. Forrest probably are voiced by the same portrayer