Fergie, 44, submitted the paperwork at the Pasadena Courthouse in California on Friday. The two announced they were separating after eight years of marriage in September of 2017.
"With absolute love and respect we decided to separate as a couple earlier this year," Fergie and Duhamel said in a statement given to ET. "To give our family the best opportunity to adjust, we wanted to keep this a private matter before sharing it with the public."
"We are and will always be united in our support of each other and our family," they added.
"We just love our kid and want the best for him," the actor expressed at the 2018 NBA Awards. "Fergie and I get along great. We have a lot of love and there's no reason to not do the best we can to raise our kid. He’s number one."