The British actor and star of The Wire shared a sweet snapshot of his new bundle of joy, showing his baby boy's tiny fingers touching his own.
"My son, Winston Elba, was born yesterday. Truly amazing," Elba Tweeted.
Elba, who made PEOPLE's "Sexiest Man Alive" list in 2013, and Garth, a make-up artist, have been together since 2013.
Baby Winston is the second child for Elba, 41, a Golden Globe winner who most recently portrayed South African President Nelson Mandela in Mandela: Long Walk to Freedom. He is also father to daughter Isan, 11.