Despite the gloomy weather, the 85,000 revellers at Balado in Perth and Kinross roared appreciation for Calvin Harris, Paolo Nutini and Pharrell Williams on the main stage.
Organisers called this year's event a "huge send-off party" as the festival prepares to move to a new home at Strathallan Castle next year after 18 years at Balado.
One of those experiencing T for the first time was Jess Hunter, 16, from Aylesbury, Buckinghamshire. "It's been an amazing weekend so far," she said. "It's a beautiful setting for a festival and the views are amazing."
Other performers included Rudimental, James, Twin Atlantic and Katy B, The Stranglers, Kiesza, Elbow, Bombay Bicycle Club, John Newman, The Human League and The 1975.
Today's headliners are Arctic Monkeys, joined on the bill by The Charlatans and Paul Weller, among others.
Festival director Geoff Ellis said: "We are delighted that so many of our devoted T in the Park fans have turned out in force to celebrate our last year at Balado and that they will be helping us to see it out in style."
The move from Balado has been prompted by health and safety concerns over an oil pipeline at the site.
Ellis said audiences had enjoyed stellar performances at the site - where there have been more than 2800 artists over the years - and singled out Beyonce and the Foo Fighters as personal highlights.
Ellis said: "We're sad to see the site go. It's been great and the local community has been brilliant, but the new site is beautiful and we're really looking forward to starting afresh and starting a new era.
"We've found somewhere that's great and can re-energise it. It will have a more boutique feel while still having the same numbers of people coming along."
Police Scotland said there had been 27 arrests since the campsite opened on Thursday, mostly for petty crime and minor drugs offences.
Nick Moore, of the Scottish Ambulance Service, said that 500 people had been treated at the hospital tent, the vast majority for minor ailments.