The stars were spotted on what appeared to be a date at the Mark's Club venue in Mayfair on Saturday (04Jul20), when the "Mamma Mia! Here We Go Again" beauty was photographed in a red dress as Evans looked dapper in an all-black suit.
According to the Daily Mail, the pair left the hotspot together and climbed into a cab to head back to Evans' hotel, where he is currently staying while preparing to return to work on new U.K.-based projects following the coronavirus shutdown.
Representatives for the actors, who are both known for keeping their personal lives private, have yet to comment on the nature of their relationship.
The outing comes weeks after James, 31, was reported to have rekindled her romance with "The Crown" star Matt Smith. They had dated for five years before quietly parting ways in December, but they were alleged to have reunited in May as they isolated together.