The 30-year-old actress nursed the infant while posing in Roberto Cavalli and Prada for the photo spread. Otis will be four months old on August 17, and is Wilde's first child with fiancé Jason Sudeikis.
"Being shot with Otis is so perfect because any portrait of me right now isn't complete without my identity as mother being a part of that," Wilde said in the interview. "Breastfeeding is the most natural thing. I don't know, now it feels like Otis should always be on my breast."
"You can be someone who is at once maternal and professional and sexy and self-possessed," the actress continued. "[But] I mean, I certainly don't really look like that when I'm [typically] breastfeeding. And there's usually a diaper involved."
Wilde's photo spread debuts during World Breastfeeding Week, August 1 to August 7. The annual event celebrates nursing mothers, and seeks to promote breastfeeding as a natural and normal act. Other celebrities, such as Alanis Morissette and Gwen Stefani, have shared photos of themselves breastfeeding in the past to help assuage resistance to mothers nursing in public.