The pair was married at Williams' home in front of about 75 friends and family members, People magazine reported Sunday.
Williams, 36, and Field, 31, met in 2006.
"At last, Rob is happy," the singer's father, Pete Conway, said in a report. "That's what you want for your kids and this is the happiest I've seen him. Ayda is so beautiful and so delightful and so lovely and just so right for him. They are brilliant together."
NBC reportedly holds celebs hostage to Jimmy Fallon's show
Aaron Carter is still in love with Hilary Duff