Scarlett Johansson, Colin Jost welcome baby boy

Marvel star Scarlett Johansson has welcomed a baby boy with husband Colin Jost, as the pair took to Instagram to reveal his adorable name.

Scarlett Johansson has given birth to her first child with husband Colin Jost.

The US actress, 36, welcomed a baby boy with the Saturday Night Live! co-host, 39, Johansson’s rep confirmed to People.

Jost took to Instagram to confirm the news, saying the pair named their son Cosmo.

“Ok ok we had a baby. His name is Cosmo. We love him very much. Privacy would be greatly appreciated,” Jost wrote, adding the hashtags #wegotawaywithitforalongtime and #we’regoingtodisneyworld.

Scarlett Johansson and Colin Jost have welcomed a baby boy, Cosmo. Picture: Amy Sussman/Getty Images

The Black Widow star already has a six-year-old daughter named Rose from her previous marriage to Romain Dauriac.

Reports first surfaced in July that Johansson was pregnant and due soon.

Just last weekend Jost confirmed for the first time his wife was expecting a baby while performing at a stand-up gig at the Ridgefield Playhouse in Connecticut over the weekend, telling the crowd: “We’re having a baby, it’s exciting.”

Johansson managed to hide her pregnancy over the last few months, giving Zoom interviews on the promotion trail for Marvel’s Black Widow that only showed the top half of her body.

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The ultra private couple got engaged in May 2019 and announced they secretly wed in October, via the Instagram page for Meals on Wheels America, a charity providing food and resources to the elderly.

The post showed a picture of the Staten Island Ferry with the words “Jost Married” across the image.

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Johansson and Jost were married in October. Picture: Matt Winkelmeyer/Getty Images/AFP

“We’re thrilled to break the news that Scarlett Johansson and Colin Jost were married over the weekend in an intimate ceremony with their immediate family and love ones, following COVID-19 safety precautions as directed by the CDC,” the caption read.

They have been dating since 2018.