O'Brien's contract allows HBO to have first look at scripted projects and long-form programming concepts developed by the anchor's Starfish Media Group.
HBO Sports president Ken Hershman, said in a statement that "Soledad is a perfect fit for Real Sports."
“She’s an extraordinary interviewer and storyteller, and we’re thrilled to be able to add her to a franchise where the emphasis is on finding and presenting thought-provoking stories in the diverse and ever-fascinating world of sports.”
Gumbel added that he was "thrilled" to be working with O'Brien.
"Soledad’s a respected journalist with a proven track record. Her credibility, broad interests and passion make her a wonderful addition to our program. I’m thrilled to have her on our Real Sports team,” he said.
O'Brien left CNN's "Starting Point" in late May after Jeff Zucker, who took over the network in 2013, decided to take her off the air.