Swift was rumoured to have signed on to play the veteran star in a biopic based on Sheila Weller's book Girls Like Us, the story of three singer/songwriters - Mitchell, Carly Simon and Carole King.
The project failed to materialise, and Mitchell has now revealed she rejected the plans.
When asked about the Swift biopic rumours in an interview with Britain's The Sunday Times, she replies, "I squelched that! I said to the producer, 'All you've got is a girl with high cheekbones. It's just a lot of gossip, you don't have the great scenes'. There's a lot of nonsense about me in books: assumptions, assumptions, assumptions."