The Circle is the name given to a tribunal authorized by President Tom Zarek that operates on Galactica. The task of this tribunal is to decide the fate of people placed on a suspect list of those implicated as collaborators during the Cylon occupation of New Caprica.
The Circle's initial members include Saul Tigh, Galen Tyrol, Samuel Anders, Seelix, Jean Barolay, and Charlie Connor. Six votes are required in order to pass judgment when "the question" concerning the fate of a suspected or implicated collaborator is raised. After the trials and executions of thirteen collaborators, Anders decides that he is no longer able to handle the emotional burden of deciding the life or death decisions made by the group. His membership in The Circle is filled by his wife, Kara Thrace.
The suspect list includes Galactica military personnel James Lyman and Felix Gaeta. The Circle convicts Lyman for perpetrating crimes against humanity and executes him by expulsion through one of Galactica's launch tubes. Gaeta, who had served as a presidential aide to Gaius Baltar on New Caprica is also convicted by The Circle of crimes against humanity. Just before Gaeta is to be executed, Tyrol is able to confirm that it was Gaeta who served as the "inside source" during the occupation of New Caprica, passing top-secret information to the resistance. Tyrol convinces the other members of The Circle to stave the execution and Gaeta is released.