He replaces Terry Moran on the late-night magazine show; Moran will become ABC News' London-based anchor and chief foreign correspondent.
Also read: Dan Abrams Drops NBC, Joins ABC News, 'GMA'
Abrams joined ABC in 2011 as a legal analyst and substitute "Good Morning America" anchor after several years in various positions at NBC. In 2009, he founded Abrams Media, which publishes sites such as Mediaite and Gossip Cop. He will step down as Abrams Media CEO to devote more time to his new position at ABC, ABC said. He will also have an expanded role at "GMA" and appear on "The Lookout."
Moran, will move to London "later this summer," according to ABC, bringing his time as "Nightline" co-anchor, which began in 2005, to an end.