Gerrard, a longtime star for Liverpool in the English Premier League, has signed with the Galaxy, Los Angeles coach Bruce Arena told the Los Angeles Times.
Gerrard signed an 18-month contract with the MLS defending champion, beginning in July.
"The time's right for myself and my family for the change, for the fresh challenge," Gerrard told the Times. "I now I feel it's the time for a fresh break and to try something different."
The signing is significant for the Galaxy, who started negotiating with Gerrard soon after Donovan announced his decision to retire at the end of the 2014 season. The 34-year-old Gerrard replaces Donovan on the field at either midfielder or forward and also replaces him in terms of name recognition and ability to attract fans.
The signing of Gerrard proves once again the Galaxy's ability to attract big-name players from the EPL. They had David Beckham and currently have forward Robbie Keane.