In Hollywood, unusual baby names are practically a rite of passage—but even global superstars aren’t immune to family pushback. Scarlett Johansson recently revealed that naming her son Cosmo sparked months of hilarious tension, emotional phone calls, and near-constant negotiations with her mother-in-law, turning what should have been a joyful announcement into an ongoing comedy of errors.
Johansson shares her son Cosmo with her husband, Colin Jost, best known as the longtime co-anchor of Weekend Update on Saturday Night Live. When the couple welcomed their son in August 2021, Jost announced the birth in classic deadpan fashion on Instagram: “Ok ok we had a baby. His name is Cosmo. We love him very much. Privacy would be greatly appreciated.” The internet laughed. The fans approved. But inside the Jost family, the reaction was… complicated.
According to Johansson, Colin’s mother was deeply unsettled by the name. “She just thought it sounded so weird,” Scarlett admitted during appearances on The Kelly Clarkson Show and later while guest co-hosting Today with Jenna & Friends. What followed was a months-long campaign of phone calls questioning whether the name was truly final. “She kept asking if we’d submitted the birth certificate yet,” Johansson said, laughing. “Like there was still time to reverse course.”
Colin Jost later confirmed the saga on Late Night with Seth Meyers, revealing that his mother repeatedly suggested alternatives she felt were more “real.” Her favorite replacement? “Cosimo.” Another suggestion—“Cosmos”—only made matters worse. Jost joked that his family seemed determined to find “a version of Cosmo that sounds less like a cartoon alien.”
Scarlett found herself in the unlikely role of mediator, trying to balance her husband’s playful creativity with his mother’s traditional instincts. The irony wasn’t lost on fans: the woman who navigated world-ending threats in the Marvel Cinematic Universe now had to negotiate peace between a Staten Island grandmother and a Saturday Night Live writer.
Over time, resistance softened. Johansson revealed that her mother-in-law finally accepted the name after meeting several Italian Americans who casually mentioned having uncles named Cosmo. “That was the turning point,” Scarlett said. “Suddenly, it was okay.”
Adding to the charm, Johansson explained that Cosmo isn’t just quirky—it’s meaningful. The name references a bright, daisy-like flower and subtly matches the floral name of her daughter Rose, whom she shares with ex-husband Romain Dauriac.
Today, the once-“weird” name has become beloved, and the family drama has turned into a favorite dinner-table story. The Cosmo saga reminds fans that even A-list celebrities deal with the same family debates as everyone else—and that sometimes, standing your ground leads to the best stories of all.