Star Wars: New Horizons Wiki:Canon Official Works

Fully canon

 * Star Wars: Knights of the Old Republic (full light-side male ending)
 * Star Wars: Knights of the Old Republic II: The Sith Lords (full light-side female ending)
 * Star Wars: The Old Republic
 * Darth Plagueis
 * Star Wars: Episode I The Phantom Menace
 * Star Wars: Episode II Attack of the Clones
 * Star Wars: Republic Commando
 * Star Wars: The Clone Wars (film and TV series)
 * Star Wars: Episode III Revenge of the Sith
 * Star Wars Jedi: Fallen Order
 * Star Wars: The Force Unleashed
 * Star Wars: The Force Unleashed II
 * Rogue One: A Star Wars Story
 * Star Wars: Episode IV A New Hope
 * Star Wars: Episode V The Empire Strikes Back
 * Star Wars: TIE Fighter
 * Star Wars: Episode VI Return of the Jedi
 * The Mandalorian

Partially canon

 * Star Wars: Rogue Squadron (final mission is non-canon)