Josh Dallas fell for Ginnifer Goodwin at first glance

Actor Josh Dallas knew "right away" he was going to settle down with Ginnifer Goodwin because he fell in love at first sight.

The stars first met in late 2011 on the set of fantasy TV series Once Upon a Time, on which they portrayed Snow White and Prince Charming, and they wed in an intimate ceremony in Los Angeles in 2014.

The couple has since added two sons to its real-life fairytale, and Josh admits their romance has worked out exactly as he imagined the moment he laid eyes on Ginnifer.

"I knew right away, it was that thing," he gushed about immediately realising the actress was 'The One'. "I turned around and I saw her and I knew I was in trouble... (I thought), 'This is it.'"

Josh frequently heaps praise on Ginnifer on Instagram, often referring to her as the "love of my life," and last May (18), he shared a sweet tribute to his wife as she turned 40.

Alongside a snap of the couple, he wrote, "Intelligence is Ginny. Elegance is Ginny. Beauty is Ginny. Grace is Ginny. Funny is Ginny. My love is Ginny. Happy Birthday to the greatest I know."

Josh insists pouring out his heart about Ginnifer online comes naturally to him, because she is everything he could ever have asked for in a partner.

"She's the greatest human I know, so that stuff is easy. That's easy to write," he smiled on U.S. breakfast show Today.

He also shared his top tips for a happy marriage, explaining, "Understanding, willing to be flexible, and just love. You gotta love and be willing to grow with that person, or let that person grow too and give them space."