Lady GaGa -- Who's That Girl?

3/14/2010 3:09 AM PDT BY TMZ STAFF
Here's Lady GaGa in her new video for "Telephone" (left) -- and Queen of Pop Madonna back around the time she was filming "Who's That Girl" in 1986 (right).

Lady Gaga and Madonna

Neither are natural blondes.

We're just sayin'.