The couple, who are expecting a boy, are throwing a co-ed baby shower on Sunday in Los Angeles, a source tells E! News.
The guest list is said to include Kate Hudson, Sharon Osbourne, Cher, Elton John, Neil Patrick Harris and David Burtka, Nicole Richie, Molly Sims, Kim Kardashian, Ryan Murphy, Brian Atwood, Adam Lambert, Zachary Quinto, Mark Jacobs and more.
Last week, Duhamel revealed the sex of the baby during an appearance on Live With Kelly and Michael.
He and his wife announced in February that they are expecting their first child, with Fergie sharing the pregnancy news via Twitter.
"Josh & Me & BABY makes three!!! #mylovelybabybump," the singer tweeted along with a photo of herself and Duhamel as children.
Sounds like somebody's one excited mommy-to-be!
—Reporting by Holly Passalaqua