Tom Cruise and Ana de Armas aren't doing anything to nix the rumors they're dating ... 'cause they were spotted hanging out in London again, further fueling the speculation.

The two stars were photographed in England's capital Friday night ... dressed causally in jeans and sneakers after hopping out of a helicopter at London Heliport.

While they weren't chatting on their walk, they both had huge smiles on their faces, clearly enjoying their time together.

No PDA here either ... but, given the recent rumors about the two of them, this pic will certainly keep fans speculating.

ICYMI ... Ana and Tom were spotted at the same heliport the night before these photos were shot -- a month after they grabbed dinner together around Valentine's Day.

The two picked up food from a restaurant -- de Armas had two takeout bags in hand -- said hello to some fans then hopped in the same taxi and took off together.

Of course, fans online immediately assumed this means they're dating ... though their relationship could be nothing more than friends and future collaborators. After all, they're both huge movie stars in the action film world.

We've reached out to Ana and Tom's teams ... so far, no word back.