Biffy Clyro's 10th Balado outing will see them become the artist which has played the festival the most times.
Oscar nominee Pharrell Williams will be another highlight, and DF Concerts have also today announced a further array of top acts which will join previously announced Arctic Monkeys and
Paolo Nutini to help wow the 85,000-strong daily crowd over July 11-13.
The T in the Park 2014 bill to date is:
FRIDAY JULY 11: Biffy Clyro, Ed Sheeran, Ellie Goulding, Bastille, Pixies, Steve Angello, Alesso, Haim, You Me At Six, Manic Street Preachers, Chvrches, Maximo Park, The Rifles, Len Faki, Pan-Pot.
SATURDAY 12: Calvin Harris, Paolo Nutini, Pharrell Williams, Elbow, Rudimental, Ben Howard, James, Bombay Bicycle Club, Twin Atlantic, The 1975, John Newman, Embrace, Katy B, Nina Nesbitt, The Stranglers, Dave Clarke, Carl Craig, Metronomy, Clean Bandit, We Are Scientists, Ella Eyre, George Ezra, Sophie Ellis-Bextor, Magda.
SUNDAY 13: Arctic Monkeys, Jake Bugg, Disclosure, Example, Imagine Dragons, Tinie Tempah, Franz Ferdinand, Kaiser Chiefs, London Grammar, Tame Impala, Kodaline, Above & Beyond, Sam Smith, Passenger, Sven Vath, Newton Faulkner, Chance The Rapper, Slam, The Twilight Sad, Inspiral Carpets, Julio Bashmore, Levon Vincent, George Fitzgerald.
Biffy Clyro cite their very first performance on the T Break Stage back in 1999 as a defining factor in the band being signed.
Guitarist and singer Simon Neil said: "It's so great to be playing this year. We've seen so many amazing bands at T in the Park over the years. Genuinely T in the Park has shaped our lives in more ways than just our experiences of performing there. We wouldn't be here, doing this now, if it wasn't for playing T in the Park. To headline it finally is amazing - it just feels poetic to be headlining on our 10th time. It's going to be the night of our lives, hopefully it'll be the night of your life and we can't wait."
Calvin Harris said: "I'm very excited that I'm going to be headlining and closing T in the Park's Main Stage. Last year was incredible, so I can't wait to be back this year. It's going to be amazing - I'll see you all there!"
Grammy Award winning singer/songwriter/producer and man of the moment Pharrell Williams is one of the most successful and prolific artists to emerge during the last decade, as part of the The Neptunes, N.E.R.D., and as a collaborator and solo star in his own right.
He featured on the two biggest selling singles of 2013 - Robin Thicke's Blurred Lines (producer, co-songwriter and featured artist), and Daft Punk's Get Lucky which he co-wrote and fronted.
This year looks set to be just as successful, with Pharrell picking up the Producer of the Year Award at the 2014 Grammys, and his hotly anticipated new album G I R L - which features the no. 1 smash hit Happy - due out next month.
Festival Director Geoff Ellis said: "Every year we ask our audience which acts they'd like to see at T in the Park, and we're thrilled to have some great acts joining us in Balado once again this summer. Biffy Clyro, Calvin Harris, Paolo Nutini and Pharrell Williams are big favourites with the T in the Park fans, and I'm sure it'll be a very special weekend. Last year's festival was one of the best yet, and 2014 is shaping up to be a brilliant weekend already, with a full day of performances on the Friday for the first time ever, plus more hours to party on the Saturday. We can't wait to see you all there."
George Kyle, Head of Sponsorship, Tennent's Lager said: "As we enter into our third decade as the T in T in the Park, we couldn't be prouder to be founding partner of this wonderful festival. We remain passionate about live music and supporting unsigned talent, which we do every year through our T Break initiative. This year will be particularly special with Biffy Clyro headlining the festival for the first time, having made their T in the Park debut on the T Break Stage. We're very much looking forward to celebrating another fantastic weekend with our partners DF Concerts and with the T in the Park fans this July."