The 'Diamonds' singer, 25, is currently spending time in the South American country and took to Instagram yesterday (18 January) to share some snaps of her trip.
And, typically, Rihanna looks sexy as hell... She can be seen showing off her peachy bum in a black thonged swimsuit surrounded by shimmering water.
With her long wet hair tousled and hanging in loose curls, Rihanna seems to be wearing little or no make-up except a splash of red lipstick.
The Bajan songstress has been sunning herself and working hard in Brazil for the last week, posing in swimsuits for a high profile magazine shoot and attending business meetings with fellow singer Shakira, who she has recently collaborated with on a new single.
Rihanna and Shakira released their brand new track 'Can't Remember To Forget You' earlier this week and have been busy promoting it ever since.
What do you think of Rihanna and Shakira's collaboration? Tell us below!
Check out more snaps of RiRi in a bikini in our gallery.
Watch the video to Shakira's single 'Can't Remember To Forget You (Audio) ft. Rihanna':