The project was announced at Comic-Con earlier this year, prompting much speculation surrounding who would play the Caped Crusader. Zack Snyder is back in the director's chair for the project, which places
Batman and Superman together on the big screen for the first time.
The film is slated to open worldwide on July 17, 2015.
The announcement comes a decade after Affleck's largely disappointing Daredevil, the 20th Century Fox pic based on the Marvel character. Released in 2003, the film grossed $180 million worldwide on a budget of about $80 million.
In 2006, Affleck played George Reeves -- who starred in the1950s TV series Adventures of Superman -- in Hollywoodland.
Man of Steel has earned more than $650 million worldwide to date.
"We knew we needed an extraordinary actor to take on one of DC Comics' most enduringly popular superheroes, and Ben Affleck certainly fits that bill, and then some. His outstanding career is a testament to his talent, and we know he and Zack will bring new dimension to the duality of this character," said Greg Silverman, Warner Bros.' president of creative development and worldwide production.
Added Snyder: "Ben provides an interesting counterbalance to Henry's Superman. He has the acting chops to create a layered portrayal of a man who is older and wiser than Clark Kent and bears the scars of a seasoned crime fighter, but retain the charm that the world sees in billionaire Bruce Wayne. I can’t wait to work with him."
The move furthers Affleck's relationship with Warner Bros. after last year's Academy Award-winningArgo, as well as his next directing vehicle, the upcoming crime drama Live by Night.
Said Sue Kroll, president of worldwide marketing and international distribution for Warner Bros. Pictures: "We are so thrilled that Ben is continuing Warner Bros.' remarkable legacy with the character of Batman. He is a tremendously gifted actor who will make this role his own in this already much-anticipated pairing of these two beloved heroes."
The as-yet-untitled superhero film is being scripted by David S. Goyer from a story he co-created with Snyder. Charles Roven and Deborah Snyder are producing, with Benjamin Melniker, Michael E. Uslan and Wesley Coller serving as executive producers. Production is expected to begin in 2014.