Kim Kardashian has officially changed her surname to West.

The US reality star revealed on Instagram that she has now dropped her famous name after tying the knot with rapper Kanye West in a fairytale wedding in Florence in May.

Kim shared an image of herself looking glamorous in a new passport picture and wrote: "New passport pic #Mrs.West #NameChange."

Kim, 33, had already been using the name Kim Kardashian West on social media, and she has previously suggested she might use Kardashian as her middle name.

The couple's daughter, who turned one in June, is named North West.