Actress Amanda Seyfried has paid a sweet tribute to her new husband Thomas Sadoski to mark his first birthday as a father.

The couple eloped in March (17), just two weeks before welcoming its first child together, a baby girl, and Amanda took to Instagram on Saturday (01Jul17) to celebrate him turning 41 with a pair of photos.

"Still can't take my eyes off you. Happy Birthday to the man of my life," she wrote beside her first picture, which featured the new mom smiling as she gazed at fellow actor Thomas while sitting on a children's pony ride.

She also uploaded a caption-less snap of the birthday boy giving her a piggyback ride while standing in front of a lake, as their dog Finn stands on his back paws to reach up to Thomas.

The stars first met in 2015, while co-starring in the Off Broadway play The Way We Get By, but their relationship didn't become romantic until they reunited for the movie The Last Word, which was filmed in 2016.

They kept much of their early romance low-key, before going public with their engagement in September, 2016, followed by their pregnancy news in November (16).

And while the name of their daughter has yet to be revealed, Amanda has been more open about their relationship on social media of late, often posting images of the loved-up pair online.

She celebrated Father's Day last month (Jun17) with a picture of her man and their furry friend Finn, and shared the message, "Happy Father's Day, Mr. @thomas_sadoski. You're doin' it so right."

The marriage is 31-year-old Seyfried's first, after previously dating her Mamma Mia! co-star Dominic Cooper on and off between 2008 and 2013, and actor Justin Long from 2013 to 2015.

The Newsroom star Thomas separated from his wife of eight years, Kimberly Hope, in October, 2015.