(CNN) -- Actress Olivia Wilde proudly announced the birth of her baby boy on Wednesday, tweeting a photo to share the news with her fans.
"Ladies and gentlemen, Otis Alexander Sudeikis has LEFT the building! (I'm the building)," she wrote.
The photo posted by the 30-year-old actress shows her smiling, with the baby's head pressed against her cheek.
Wilde and former "Saturday Night Live" star Jason Sudeikis welcomed their newborn on April 20, a representative for Wilde said.
The couple announced their engagement last year and revealed in October that they were expecting their first child together.
"We've discussed all our ideals and hopes. I can't wait for children," the "Rush" star told Marie Claire last year. "I'm open-minded about how many, but three, which I love, is like a little party. ... (T)here's no strict plan for anything in my life. What happens, happens."
But even then Wilde said she knew her husband-to-be would make a great dad.
"He's so good with kids," she told the magazine of Sudeikis, 38. "I've never before experienced looking at someone and thinking, 'That's who I want to raise a child with.' "
CNN's Breeanna Hare and Jane Caffrey contributed to this report.