In his new role as executive vice president, he will work alongside publisher and president Dan Buckley to bring Marvel properties to the small screen.
Loeb will help to develop live-action and animated projects based on the publisher's characters, and take charge of the production and distribution of direct-to-DVD projects.
"I couldn't be happier to accept this new position at Marvel Entertainment, working with both Dan and Alan [Fine] to deliver exciting, cutting-edge television projects," said Loeb.
"Marvel continues to break new ground in storytelling in both their comic book and film ventures, so, along with everyone here, I'm excited to bring the same brand of excitement into homes across the globe."
Loeb previous held an exclusivity contract with Marvel as a writer on titles such as Iron Man, Captain America, Hulk, Daredevil, Spider-Man and X-Men.