Kara Thrace (call sign "Starbuck"), portrayed by Katee Sackhoff,[2][3] is a gifted Viper pilot, with a volatile attitude that has hindered her career in the Colonial Fleet.
Lee Adama (call sign "Apollo"), portrayed by Jamie Bamber,[4] is a former Colonial Fleet Reserve officer who is appointed Galactica's CAG (Commander of the Air Group) after the Cylon attack.
The copy dubbed "Caprica Six" is considered a hero for her infiltration of the defense systems of the Twelve Colonies, which facilitated the cataclysmic Cylon attack.
Athena poses as Sharon Valerii for an unsuspecting Karl Agathon to help him escape Caprica, and subsequently falls in love with him while trying to earn the trust of the Galactica crew.
[6] Screen Rant's Craig Elvy wrote that Tigh's best moment of character development in the series was the death of his troublesome wife Ellen at his hands, though it was later rendered "meaningless" by her resurrection.
[7] Galen Tyrol (often called "Chief"), portrayed by Aaron Douglas,[3] is the Galactica's highest-ranking non-commissioned officer and in charge of maintenance of the Vipers and Raptors.
[5] Screen Rant wrote that Tyrol stands out thanks to "complex relationship with Sharon Valerii and his quest for redemption", which "highlights the show's theme of breaking the cycle.
She begins dating President Laura Roslin's aide Billy Keikeya, but eventually cheats on him with Viper pilot Lee Adama.
Felix Gaeta, portrayed by Alessandro Juliani,[8] serves as tactical officer on the Battlestar Galactica during the destruction of the Twelve Colonies and the ship's subsequent escape from the Cylons.
Gaeta is shown to be in a romantic gay relationship with Lieutenant Hoshi of the Pegasus in the web series Battlestar Galactica: The Face of the Enemy.
"[11] Alex Quartararo (call sign "Crashdown"), portrayed by Sam Witwer,[12] is a Raptor Electronic Countermeasures Officer from the destroyed Battlestar Triton who joins the Galactica crew.
Though seemingly immune to interrogation tactics and physically capable of breaking his bonds, Leoben tells Kara Thrace that he has hidden a nuclear bomb somewhere in the fleet.
Leoben tells Kara that she has a special destiny, and that the humans will find their original homeworld, Kobol, which will lead them to their fabled promised land, the planet Earth.
As the human Resistance overcomes the occupying Cylons in "Exodus", Kara tells an expectant Leoben "I love you" with a kiss, distracting him enough to kill him and take Kacey.
He sells the idea to the leader of his faction, a Six named Natalie Faust, in "Faith", and they negotiate with Roslin in "Guess What's Coming to Dinner?".
When the Galactica is overtaken by a mutiny, Roslin flees to a Cylon Basestar, and a Two helps her defeat the Battlestar's jamming signal so she can transmit a message to the entire fleet.
Screen Rant described Leoben as a "serious threat" to both Cylons and humans thanks to his "deceptive and manipulative skills", noting that at times he is "unsettling" and "deliciously twisted", and sets "a dark and mysterious tone" in the series.
As the attacks on the Twelve Colonies commence, Doral bristles when then-Secretary of Education Roslin takes command of the starliner they are on, but is shut down by Lee Adama.
Unwilling to take a chance in their current situation, Colonel Tigh maroons Doral with basic rations at the Ragnar Anchorage munitions depot.
Introduced in "Bastille Day", he leads a riot and later runs for political office, is elected vice-president and resists military domination of the civilian government.
Dr. Sherman Cottle, portrayed by Donnelly Rhodes,[15] is the Galactica's Chief Medical Officer, introduced in the season one episode "Act of Contrition".
[5] Another copy is the former doctor of the Caprica Buccaneers, who now serves as the medic to the human Resistance group made up of the team's former players, including Sam Anders, fighting against the Cylon occupation of the planet.
President Roslin and Commander Adama grant her full access, believing that D'Anna will discover that military personnel deal with the same pressures and fears as the rest of the fleet, and that the events were a tragic mistake.
D'Anna's glowing report is broadcast to the entire fleet, but is also viewed by copies of Cylon models Six, Sharon and Doral, its transmission made possible by the staged Raider attack.
The supernova of a local star activates a crystal vision mechanism that shows D'Anna the identities of the Final Five, but she dies before she can tell Baltar what she saw.
In "Sometimes a Great Notion", the humans and Cylons to leave find a new habitable planet, but D'Anna decides to stay on Earth and die with her ancestors, ending the cycle of death and rebirth.
[5] Screen Rant wrote "What makes [D'Anna] stand out is her sheer force of will, which continues to transcend allegiances and loyalty throughout the entire series.
While she was generally loyal to the Cylons, her obsession with unveiling the Final Five and understanding the truth behind the Cylon-Human conflict leads her to take extreme measures to meet her goals.
"[6] Tory Foster, portrayed by Rekha Sharma,[3][6] is introduced in the season two episode "The Captain's Hand" as President Laura Roslin's new aide, in the wake of Billy Keikeya's death.
Unlike Tigh, Tyrol and Anders, the revelation is liberating for Tory, and she is quick to align herself with the rebel Cylon factions who seek an alliance with the humans.