Josh Hartnett and Tamsin Egerton are expecting their first child together.
A representative for the Penny Dreadful actor confirmed the happy news to E! News.
The couple had an on-screen romance in The Lovers, which was filmed in 2010 and 2011, with rumours of an off-screen relationship reported in 2012, but it wasn't until the following year that the pair went public.
Harnett told American daily newspaper USA Today in May of their decision to keep their romance private, "I purposefully didn't want people to know too much about my personal life because I think a lot of people give it away for free.
"I think if you spend too much time courting people's attention into your personal life, you lose your ownership of it. That's why I make sure my life is my own. I was not a dumb kid. I was a little bit wary of this business. I saw what it could do to people pretty quickly."
