The star posted a video this evening on Instagram of what appears to be him celebrating in a room at St Thomas’ hospital overlooking the House of Commons at the Thames in London.
Beside a bunch of white flowers there’s a congratulatory message from Gucci, saying : “Dear Barry and Alyson, Wishing you both a huge congratulations on the birth of your newborn baby! From all your friends at Gucci xx.”
Barry (29) wrote: “Thank you [Gucci]” , posting alongside a baby face emoji and three red love hearts.
Little is known about the Dubliner’s girlfriend Alyson Sandro, and they have been dating for just over a year.
In March the couple announced they were expecting their first child together.
At the time Barry posted a photo at a baby shower jumping for joy, with the caption: "I don’t know why others have there opinions. WE ARE HAPPY HERE."
It sounds like despite his privacy about the nature of his and Alyson's relationship, there are a few voices of dissent.
Earlier this year he posted a picture of himself and Alyson posing in the mirror together, with his arms wrapped around his partner’s tummy as she showed her baby bump.
Barry and Alyson made their red carpet debut together at the premiere of Eternals last October.
The actor previously had a long relationship with Kerry makeup artist Shona Guerin, who he once told Lucy Kennedy on a TV programme: "I’d be lost without her. I’m telling you that. I wouldn't be the man I am now without her."
Barry also pointed out that his co-stars, Colin Farrell and Cillian Murphy, once gave him some words of relationship advice. "Any of the lads I work with, Colin [Farrell], Cillian [Murphy], they're always like, 'Don't mess this up. They see how important she is’."
Last August the Sunday World reported how Barry had been the victim of a mystery assault in Galway, after being found battered and bruised outside the G hotel.
He was rushed by ambulance to Galway University Hospital, where he was treated for his wounds and later released.
The young star first sprang to fame in 2013 as the ‘cat killer’ Wayne in RTE’s crime series Love/Hate, having started his acting career in 2011 after answering an advertisement for ‘Between the Canals’ when he saw a casting notice in a local shop window.
He grew up in the Summerhill area of north inner city Dublin, close to where Olympic gold medallist Kellie Harrington hails from.
Barry also briefly featured in Fair City, but 2014 saw him win his cinema breakthrough role in the Northern Ireland set flick ’71, which starred Jack O’Connell in the lead part
He then featured as George Mills in Dunkirk and started as Martin Lang in The Killing of a scared deer, alongside Colin Farrell and Nicole Kidman and for which he won an IFTA awards for Best Supporting Actor.
The following year he was in Black 47, as Hobson, an English soldier stationed in Ireland.