(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.
Ladies and gentlemen, Otis Alexander Sudeikis has LEFT the building! (I'm the building) pic.twitter.com/uHfY3adroc— olivia wilde (@oliviawilde) April 23, 2014
"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.
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