Johansson’s representative Marcel Pariseau confirmed to people.com.
The Black Widow actress is also mom to daughter Rose Dorothy, who turns 7-years-old this year.
Jost briefly mentioned their pregnancy news during a stand-up performance at The Ridgefield Playhouse in Connecticut Sunday, a source confirmed to people.
On Instagram later Wednesday, Jost shared a statement revealing that they welcomed a baby boy named Cosmo.
He wrote: “Ok Ok we had a baby. His name is Cosmo. We love him very much. Privacy would be greatly appreciated.”
Johansson and Jost got married in an intimate ceremony in October 2020.
The couple got engaged in May 2019 after two years of dating. The actress showcased her 11-carat glittering engagement ring that July while taking the stage at San Diego Comic-Con.
In October 2019, Johansson told TV personality Ellen DeGeneres that Jost “killed it” with his “surprising” proposal, which included “a whole James Bond situation.”
Johansson has previously been open about parenting her first child. In April she talked about how she encourages Rose to eat healthy meals.