Olivia Wilde and Jason Sudeikis will marry next spring.

The Tron actress and her Saturday Night Live star fiance will tie the knot in a ceremony in upstate New York and the bride-to-be has already chosen Monique Lhuillier to design her bridesmaids' dresses.

According to the New York Post newspaper, the actress was overheard at a dinner at The General in New York on Monday telling guests about her wedding plans, and also joked that having a long engagement bucked a family trend of marrying just months after a proposal.

Olivia - who announced her engagement to Jason in January - has previously admitted she can't wait to start a family with her 37-year-old fiance: "[I] can't wait for children. I'm open-minded about how many, but three, which I love, is like a little party. I am not trying to have kids now - there's no strict plan for anything in my life. What happens, happens. [Jason's] so good with kids ... I've never before experienced looking at someone and thinking, 'That's who I want to raise a child with.'"