"Happy New Year," the 39-year-old captioned an Instagram pic.
The actress put on a big smile for the camera as she showed off her slim figure. She reclined back on an indoor hammock and strategically covered her modesty with her hands, reported Us magazine.
During her tropical getaway, Reid also went swimming.
"Caves are so beautiful in Tulum. I love it. Wish you were all here with me," she captioned the picture.