While preparing for Christmas at the Winter Street Inn, Kelley Quinn and his family find the holiday season thrown into chaos when three of their exes show up.

Christmas on Nantucket finds Winter Street Inn owner Kelley Quinn and his family busily preparing for the holiday season. Though the year has brought tragedy, the Quinns have much to celebrate: Kelley has reunited with his first wife Margaret, Kevin and Isabelle have a new baby; and Ava is finally dating a nice guy. But when Kelley's estranged wife Mitzi shows up on the island, along with Kevin's devious ex-wife Norah and a dangerously irresistible old fling of Ava's, the Inn is suddenly overrun with romantic feuds, and it's going to take a whole lot more than a Christmas miracle to get the Quinns-- and the Inn-- through the holidays intact.