The Marvel hero, 34, and the Saturday Night Live co-host and writer, 36, cozied up to each other on the red carpet, smiling at each other and posing for pictures, with Johansson stunning onlookers with a silver strapless dress. Jost, meanwhile, rocked a black tuxedo for the outing.
Along with almost the entire Avengers cast, additional attendees at the star-studded carpet included Katherine Schwarzenegger, (who attended with fiancé Chris Pratt), and married couple Miley Cyrus and Liam Hemsworth.
Johansson and Jost first made their public debut as a couple in November 2017, and they heaped on the PDA together in an SNL appearance the following month. Since then, they have met each other’s families and spent time with the actress’s 4-year-old daughter Rose (from her marriage to Romain Dauriac) at Disneyland in California in March.
Although the couple has not yet reached an engagement, the possibility looms, as a source told PEOPLE last month, “There is marriage talk with Colin.”
“Scarlett and Colin are in love and share many of the same interests and the same sense of humor,” the insider said. “Scarlett is very happy.”
Johansson was previously married to Ryan Reynolds and journalist Romain Dauriac.
Avengers: Endgame opens Friday.