It inspired us all to ignore the haters, live our best lives, and accept the fact that we probably can't dance.
But now Taylor is being sued for $42 million over one of the song's most recognisable lyrics.
Musician Jesse Graham is filing a lawsuit against Taylor, claiming that she stole the lyrics "The haters gonna hate / The players gonna play" from a song he wrote in 2013.
"Her hook is the same as mine," Graham told the New York Daily News. "If I didn't write the song 'Haters Gone Hate,' there wouldn't be a song called 'Shake It Off' ... At first I was going to let it go, but this song is my song all the way."
Here are the two songs side-by-side, for reference:
