"I've decided to become a member of the Houston Rockets," Howard wrote in a Twitter post. "I feel it's the best place for me and I am excited about joining the Rockets and I'm looking forward to a great season. I want to thank the fans in Los Angeles and wish them the best."
The free-agent negotiating period opened on Monday. Contracts can’t officially be signed until July 10.
Howard also changed his Twitter image to a picture of himself wearing a Rockets jersey.
The official declaration came after a day of conflicting reports over Howard's future. The All-Star center escaped to Aspen, Colo., for the July 4 holiday to mull his future after holding free-agency meetings with the Rockets, Lakers, Warriors, Mavericks and Hawks earlier this week.
"Welcome to Houston, Dwight Howard," Rockets GM Daryl Morey wrote on Twitter. "Years of work by Dwight and Rockets went into this. This team is going to be special."
Exactly who will be on that team isn't yet clear. Howard is expected to team up with All-Star guard James Harden and small forward Chandler Parsons, while center Omer Asik and guard Jeremy Lin saw their names floating in trade rumors Friday. "Everybody welcome my boy Dwight Howard to the Houston Rockets," Parsons tweeted on Friday. "New age."