Gillian Foster
Gfoster 1
Character info
Portrayed by Kelli Williams
Gender Female
Hair color Brown
Eye color Blue
Family Alec Foster (ex-husband)

Sophie (former adopted daughter)

First Seen Pilot
Last Seen Killer App
Affiliation The Lightman Group

Dr. Gillian Foster is a psychologist who is Dr. Lightman's colleague in The Lightman Group.

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Early LifeEdit

Before the show began, Gillian and Alec adopted a baby, Sophie, but only made it to day 57 before the birth mother, who had 60 days to change her mind about the adoption wanted Sophie back.

On Lie to MeEdit

Gillian is the Lightman Group's resident psychologist. 


Alec FosterEdit

Alec and Gillian had a loving relationship, even attempting to adopt a baby before the show's Pilot. It was shown several times on the show that he is lying to Gillian about something, and that Cal knows, much to Torres' dismay. However, it is shown that he is not unfaithful, as originally thought, and instead had relapsed back into doing drugs (cocaine). They later divorced. 


  • This character is based on Dr. Maureen O'Sullivan, a psychology professor at the University of San Francisco who helped Paul Ekman (on whom Cal Lightman is based) in the discovery of microexpressions and the creation of The Paul Ekman Group. Foster's character is mild-tempered and almost saintly. She is very motherly especially to Lightman.

Gallery Edit

Characters of the Lie to Me Series
Main Characters
Dr. Cal LightmanDr. Gillian FosterEli LokerRia TorresEmily LightmanBen Reynolds
Recurring Characters
Zoe LandauKarl DupreeAlec Foster