A preview of Taylor Swift's new single has been leaked online.

'Speak Now' is the second track to be taken from her third studio LP of the same title, which is due to be released in the US on October 25. The album is a concept record and the follow-up to her 2008 mulitplatinum 'Fearless'.

A 30-second clip of the song, due out a week prior to the album, was leaked onto YouTube this morning.

Speaking about 'Back To December', Swift said, "After I wrote it, I realised that I've never apologised to someone in the song. This album is about my confessions."

Watch a video about Taylor Swift and 'Speak Now' below: