The Luther actor, 41, welcomed his newborn son yesterday (17 April) and announced the good news to his one million Twitter followers.
Alongside a heartbreakingly cute black and white photo of his baby son clutching his finger, Idris wrote: "My Son Winston Elba was born yesterday..Truly Amazing :-)."
Idris is said to have chosen the name in honour of his late father Winston, who died last September following a battle with lung cancer.
Winston is Idris' first child with make-up artist girlfriend with Naiyana Garth.
The Wire's Idris already has a daughter called Isan, 11, with his ex-wife Dormowa Sherma.
Idris and Naiyana have been officially dating since March 2013 and announced she was expecting shortly after.
The heartthrob recently made a huge name for himself in Hollywood after starring as Nelson Mandela in Mandela: Long Walk To Freedom.
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