The singer confessed that she gets confused when she spots a familiar face, which can sometimes lead to "embarrassing" situations.
"It's really weird. Usually when I see someone famous, for some reason, I think I know them," Lewis told New! magazine.
"I've approached people so many times just because they are a familiar face. I smile at them and go to talk to them and clearly they don't know me!
"I've done it to Taylor Lautner from Twilight and a few of the EastEnders actors too. It's really embarrassing, but I do it all the time!"
Lewis recently revealed that she is still wary about crowded places after she was attacked at a book signing in 2009.
Watch Leona Lewis's video for 'Trouble' below: