Ferg touched down in Rio Wednesday, and tried to draw eyes away from her leggy leopard-print outfit and knee-high boots by holding up her left hand. She flaunted 4 rings spelling out F-E-R-G. Mind you, this was the day before she and Josh announced their separation.

As we reported, they split earlier this year, and say they took time to adjust before announcing it.

Fergie's down there to perform in the Rock in Rio music festival. Josh is back home with their son, Axl, and was seen Wednesday ... still wearing his wedding band.