A source confirms to PEOPLE that the couple tied the knot Sunday night at Boone Hall Plantation in Mt. Pleasant, S.C., just outside of Charleston.
The reception took place in a white tent at the plantation on Sunday evening. Florence Welch (of Florence and the Machine), a good friend of the Gossip Girl star, performed three songs live, and there was also a deejay who spun tunes. PEOPLE also confirmed that a cake was being driven down from Virginia for the event.
Lively's mother and sister were also spotted in town, and a source told PEOPLE that the two had dinner in Charleston with Bette Midler earlier in the weekend.
Reps for the two actors had no comment.
Lively and Reynolds have been in nesting mode since buying a home in Bedford, N.Y., earlier this year. They have subsequently been seen working out together at a local gym, as well as spending quality time with their families in New York and Vancouver, where Reynolds, PEOPLE's 2010 Sexiest Man Alive, was born.
The two, who costarred together in 2011's Green Lantern, have stayed relatively mum about their relationship, though Lively, 25, did tell Marie Claire this summer, "It's definitely attractive when a man can dress well."
Reynolds, 35, was previously married to Scarlett Johansson. The couple divorced in 2010 after two years of marriage.
This is the first marriage for Lively, who previously dated her Gossip Girl costar Penn Badgley.