Daniel Radcliffe expecting first child with long-term partner Erin Darke
A representative for the 33-year-old Harry Potter star confirmed the news to the PA news agency on Saturday.
Radcliffe, who played the titular character in the film franchise based on JK Rowling's best-selling book series, and American actress Darke, 38, are preparing to become parents for the first time.
The pair are reported to have met on the set of 2013 film Kill Your Darlings.
Radcliffe, whose other film roles include 2012 horror The Woman In Black and 2016 comedy Swiss Army Man, divides his time between the UK and US, with Darke.
Michigan-born Darke is best known for her role in 2015 series Good Girl Revolt, and more recently appeared in Prime Video series The Marvelous Mrs Maisel.
Radcliffe starred in the lead role in Weird: The Al Yankovic Story, which was released last year.
The biopic follows the life and career of comedian Weird Al Yankovic who rose to fame with comical spoof versions of classic songs.