Betraying his knowledge of pop nerd culture, at a point during the game, your elite hacker cries out "FEAR MY ELITE HAXOR SKILLZ!", which has become a standard slogan for both nerds and hackers alike.
Del Rey published a pair of novels by Karen Traviss tieing-in to this video game: Hard Contact (2004) and Triple Zero (2006).
Republic Commando is one of the few Star Wars licensed titles that does not feature the trademark opening. In other Star Wars videogames and the movies, the Star Wars logo is first displayed followed by scrolling text narrating the backstory.
Your in-game serial number, RC-1138, is a reference to one of George Lucas' early films: THX-1138.
Temuera Morrison, who plays Jango Fett in Star Wars: Attack of the Clones, lend his voice to Delta 38.