BO-661 was a male soldier who belonged to the Human species. He fought for the Galactic Empire throughout the Galactic Civil War.
BO-661 was a Galactic Marine stationed at the Detainment Facility within the Imperial Fortress located on Yavin 4. His service began after the battle of Yavin. In the year 1 ABY, the Empire took six Rebel pilots prisoner and incarcerated them at this facility. During the Remembrance Day celebrations that same year, Wedge Antilles, an Officer in the Alliance Starfighter Corps, orchestrated a rescue mission involving a group of loyal Rebel spacers to free the imprisoned pilots. These Rebel operatives launched an assault on the prison, resulting in BO-661's death. Following this, one of the spacers took his armor so a Rebel pilot could disguise themselves and escape the base undetected.
BO-661 appeared as a non-player character in Star Wars Galaxies, a massively multiplayer online roleplaying game that was released in 2003. The game was developed by Sony Online Entertainment and published by LucasArts. The game shut down on December 15, 2011. BO-661 was introduced to the game with "Game Update 11," which was released on June 23, 2009. He was present during the Empire Day events in 2009, 2010, and 2011.