Martin, 40, and Johnson, 28, were spotted grabbing dinner together at a sushi restaurant in Los Angeles on Tuesday night, a source tells PEOPLE.
They were “cozy, laughing and affectionate,” says the source, adding that it was just the two of them at dinner.
Martin and Johnson’s reps have not responded to PEOPLE’s request for comment.
The Coldplay singer was last linked to British actress Annabelle Wallis. The two began dating in August 2015, and were often spotted together as the singer toured with his band.
Martin was married for 10 years to Gwyneth Paltrow before they “consciously uncoupled” in March of 2014. The two have remained close, often spending time with their children, Apple, 13, and Moses, 11, together.
Johnson previously dated model/rocker Matthew Hitt. The two have been on and off for years, but were last seen together in 2016.
The actress next reprises her role as Anastasia Steele in Fifty Shades Freed, which opens Feb. 8, 2018.