Captain Aaron Kelly is a fictional character, played by Ty Olsson, in the reimagined Battlestar Galactica TV program. The character has been part of the show since the 2003 Miniseries. Captain Kelly is the landing signal officer (LSO) aboard the Battlestar Galactica. At the beginning of the second season, Captain Kelly was third in line of command, after then-Commander Adama and then-Colonel Tigh. The character of Aaron Kelly has no direct analog in the original Battlestar Galactica.
Captain Kelly is first shown greeting then-Commander Adama in a corridor before the decommissioning ceremony for the Galactica. Later in the miniseries, Kelly is shown collecting the dogtags of the fatalities of the Cylons' earlier nuclear attack on the Galactica.
Kelly becomes executive officer of Galactica after Adama is shot and falls comatose, and Tigh becomes commanding officer and commander of the fleet. After the fleet jumps using out-of-date coordinates, resulting in Galactica ending up alone, Kelly strongly voices his opposition to Felix Gaeta's plans to network Galactica's computers together to find the rest of the fleet.
Kelly is shown performing his duties as LSO in the second-season episode "Final Cut". He is on duty when Louanne "Kat" Katraine panics and finds herself unable to safely land her Viper due to stimulant abuse. This episode was also the first to give the character's first name as Aaron.
Kelly is still serving aboard the Galactica when she jumps away from New Caprica to avoid the Cylon invasion fleet. He serves in the CIC during the Battle of New Caprica, in which Galactica fights a holding action to allow the civilian population to escape from the Cylons. Two weeks before the trial of former President Gaius Baltar is set to start, Kelly assassinates his first public defender and attempts to kill his second lawyer twice. When then-Major Lee Adama uncovers the plot and confronts Kelly, disciplinary actions are taken against him.