The 25-year-old actress announced the separation via her Instagram story.
Lena Headey, 49, and Marc Menchaca, 47, have been romantically linked since 2020.
Their small intimate wedding was held at a church in Ireland.
The 42-year-old actor was driving his 1970 Oldsmobile at 11 am when motorcyclist Vitaliy Avagimyan, 21 crossed the double yellow lines of Old Topanga Canyon Road.
“I am in the really, really, really small minority of people that can survive that," she said.
The couple had welcomed their first child- daughter Willa on July 22, 2020.