The pair posed for pictures on the steps of the register office with a small group of family members, reported People magazine.
The 57-year-old actor was wearing a dark blue suit, while Eberstein, 39, was dressed in a blue shirt and white skirt, and sported gold wedding band.
Eberstein is the mother of three of Grant's children. In 2012, the couple had their first child together - a son. The pair then had a daughter, whose name has not been revealed, in December 2015.
Grant also has two children - Tabitha and Felix - with former partner Tinglan Hong.
The actor also dated Jemima Khan in the past.