Caprica Six
Caprica Six is the second copy introduced in the show, she is very religious and her seduction of Gaius Baltar gave her the ability to destroy Caprica. In the process, she fell in love with Gaius, her love for a human ends up allowing herself to change the view of other Cylons. Caprica becomes an integral cylon in helping begin a relationship with humans and cylons alike. She is one of the leaders on New Caprica, hoping that humans and cylons can live together. When Galactica comes to the aid of their people she flees with Gaius and lives on a basestar. When Athena finds out her daughter is aboard the basestar, and is very ill, she goes to the rescue of her daughter. Caprica sees that things are not going well and decides to aid Athena in the rescue of Hera. Back on board the Galactica, she is captured and put into captivity immediately. She later begins a relationship with Colonel Tigh, and eventually is revealed to be pregnant. An alliance is formed with the humans and Caprica, along with the others involved in the alliance are given amnesty and she is released from captivity.

Baltar's Internal Six
Baltar's internal Six is feisty, yet at the same time very religious. She aids Baltar in a time of need by recommending different things to say and different things to do that help to save his life. She may be a figment of his imagination, but this Six is a very interesting one.

Shelly Godfrey
A copy of Number Six that physically appears on board Galactica to try to discredit Baltar as a traitor, using evidence which was flawed, so that he ended up being more popular than before.

Gina Inviere
A copy of Number Six posing as a systems analyst assigned aboard the battlestar Pegasus. A after she was identified, she was captured and repeatedly tortured and sexually abused by the crew before escaping with Baltar's help. Emerging as a leading figure in the Demand Peace movement, she commits suicide by detonating a nuclear warhead aboard Cloud 9.

Natalie
Natalie is a copy of Six, notably different with her long brunette hair, that leads the "rebel" Cylons after they break apart from their counterparts. She helps in forming an alliance with the humans, and ends up helping destroy the resurrection ship after she notes that she believes the cylons will live life to the fullest if they know that they have one chance to live. She is murdered by Athena, when in a panicked state, she believes Natalie was going to kidnap her daughter Hera.

Armistice Station Copy
Number Six is a portent of doom for the peoples of the Twelve Colonies; she arrives on Armistice Station shortly before it is destroyed in what are the opening shots of the Cylon attack in the Miniseries. Dressed in a long-sleeved red tunic and matching knee-length skirt, she is the first and last "diplomat" ever sent to the station by the Cylons since its construction. She greets the Colonial officer present with the question "Are you alive?" When he answers that he is alive, she tells him to prove it - by kissing her. After he realizes that Armistice is under attack, she smiles and forces another kiss on him shortly before they are both destroyed. Later, three Sixes in the same outfit are among the group of Cylons that rescue and debrief Aaron Doral, following his stranding on Ragnar Anchorage by the suspicious Colonials. One of them responds to a comment of the Eight in the group with "By your command," a trademark Cylon phrase in the Original Series.