The Scottish Wildlife Trust said the bird flew into the reserve at Loch of the Lowes, near Dunkeld, early yesterday.
The female osprey, estimated to be in her late 20s, has been returning to the reserve for the past 24 years and could be the oldest breeding osprey in the UK.
She returned at 6.49am yesterday morning, and was confirmed as the famous female using close-up images of her plumage and eye markings.
The male breeding osprey returned on March 21 and they have already began their courtship, so now there is speculation as to whether the pair will produce any chicks this season.
The Scottish Wildlife Trust's Perthshire Ranger, Emma Rawling, said: "Everyone at the Scottish Wildlife Trust's Loch of the Lowes Visitor Centre is thrilled our resident osprey has returned.
"She is a very old bird and for her to undertake another successful migration is testament to just how special she is, however, it does demonstrate the conservation success story of the species as a whole.
"The questions now are whether she will breed, if any eggs will hatch and whether any chicks fledge."