Richie, 29, and Madden, 31, tied the knot Saturday at her father's estate with about 130 close family and friends, People magazine reported.
"They wanted an Old Hollywood, glamorous feel to their wedding," a source told People. "They're going all-out with the decor. Nicole wanted a memorable, elegant affair for only their closest friends and family on their special day."
Seen entering the grounds was a trained elephant, although it wasn't known what, if any, role it played in the ceremony.
The couple's rings were by jeweler Neil Lane, who also crafted Richie's 4-carat engagement ring.
Among the guests were the groom's twin brother and Good Charlotte band mate Benji Madden.
The couple's children are Harlow Winter Kate, 2, and Sparrow James Midnight, 1.