Tom O'Neill was both an illustrator and a graphic artist. He contributed his talents to West End Games' Star Wars: The Roleplaying Game supplementary books. Furthermore, he took on the role of art director for both Lords of the Expanse and Alien Encounters.
- Alien Encounters (Design, graphics)
- Classic Campaigns (Graphics)
- Cracken's Threat Dossier (Cover design, graphics)
- Creatures of the Galaxy (Interior artist)
- The DarkStryder Campaign (Graphics)
- Galaxy Guide 6: Tramp Freighters, Second Edition (Graphics)
- Galaxy Guide 10: Bounty Hunters (Graphics)
- Heroes & Rogues (Cover design)
- Hideouts & Strongholds (Cover design)
- Imperial Double-Cross (Graphics)
- The Jedi Academy Sourcebook (Graphics)
- Platt's Starport Guide (Cover design, graphics)
- Pirates & Privateers (Cover design, graphics)
- Star Wars Miniatures Battles Companion (Graphics; as Thomas O'Neill)
- Star Wars: Shadows of the Empire (Cover design, graphics)
- Star Wars Adventure Journal 1 (Graphics)
- Star Wars Adventure Journal 2 (Graphics)
- Star Wars Adventure Journal 4 (Graphics)
- Star Wars Adventure Journal 6 (Graphics)
- Star Wars Adventure Journal 12 "Idol Intentions" (Interior artist)
- Star Wars Adventure Journal 13 (Cover design, graphics)
- Star Wars Adventure Journal 14 (Graphics)
- Star Wars: The Roleplaying Game, Second Edition, Revised and Expanded (Artistic design, graphics)
- Star Wars Trilogy Sourcebook, Special Edition (Cover design, graphics, layout)
- Stock Ships (Art director)
- Tapani Sector Instant Adventures (Cover design, graphics)
- The Truce at Bakura Sourcebook (Cover design, graphics, interior artist)
- Wretched Hives of Scum & Villainy (Interior artist)