"What It Is" is a song written and recorded by the British rock musician Mark Knopfler.

It was released on 4 September 2000 as the lead single from his second solo studio album, Sailing to Philadelphia (2000).

An extended version of the song released in Mexico contains an additional verse: The song's lyrics pay homage to the city of Edinburgh, Scotland, making reference to Edinburgh Castle, the Stone of Scone and Canongate Tolbooth.