The executive officer (abbreviation: XO) is the second in command aboard a Colonial Fleet vessel and is responsible for administrative duties and the detailed management of affairs, giving the commanding officer time to deal with broader issues.
The rank normally held by the executive officer of a battlestar is Major or Colonel, though an officer of any rank can fill this billet.
- For a complete history of Galactica's XOs see: Senior Staff of Galactica
- Colonel Saul Tigh ("Miniseries" to "Lay Down Your Burdens, Part II")
- Captain Karl Agathon ("Occupation" to "The Passage")
- Colonel Saul Tigh ("The Passage" to "Daybreak")
Executive Officer, battlestar Pegasus
- Colonel Jurgen Belzen (shot by Admiral Cain for disobeying an order in "Razor")
- Colonel Jack Fisk ("Razor" to "Resurrection Ship, Part II")
- Commander Fisk's XO is unknown. A deleted scene from "Black Market" shows Captain Renner as Fisk's XO. However, he doesn't appear in the aired episode and is never mentioned again in the series. This makes his canonical status questionable.
- No Executive Officer is mentioned under Commander Barry Garner, during whose stint Lee Adama effectively performed that position's duties, probably without holding the position.
- Major Kendra Shaw (an indeterminate amount of time during "Razor")
- Lieutenant Anastasia Dualla ("Lay Down Your Burdens, Part II" to "Exodus, Part II")
- Executive Officer, in the military context, is used in several branches of armed forces worldwide (army, naval, marine, air force). Certain forces, such as the British Army use the formal title "Second-in-Command" (2i/c) rather than XO.
- It should be noted that when chosen to become the XO, Kendra Shaw is promoted to the rank of Major, presumably the minimum rank required to hold this billet. However, we later see Anastasia Dualla acting as Executive Officer with the rank of Lieutenant after the settlement of New Caprica, although this might have to do with having only a skeleton crew assigned to the ship.
- While Lee Adama is assigned to Pegasus in "The Captain's Hand", it is doubtful that he was the official XO at that time. According to dialogue he is only sent over to keep an eye on Garner and assess the situation but Garner doesn't even consider him part of the crew. Moreover, according to a deleted scene, his father sends him there over concerns about Garner and the performance of the crew, while being undecided on whether to make him the ship's XO or not.