We spotted Rihanna leaving a London hotel wearing a sheer, white jersey ensemble that revealed her bra underneath. The actress looked quite sporty with matching sneakers and sunglasses. Notice her slightly grey locks?
Other celeb sightings:
Kristen Stewart, dressed in full military uniform, filmed scenes for her upcoming movie "Camp X-Ray" in Los Angeles.
Owen Wilson rode his bicycle through the West Village in New York City.
George Clooney's ex-girlfriend Elisabetta Canalis stepped out in a bikini at the hotel Regina while on vacation in Ischia, an island off the coast of Italy.
Alessandra Ambrosio attended the launch of Always Platinum Collection at Casa Petra in Sao Paulo, Rio de Janeiro.
Check out more photos of celebrities out and about...