Julianne & Derek Hough Perform with Sia on 'DWTS' Finale!

Julianne and Derek Hough perform a dance together on the season finale of Dancing With the Stars on Tuesday evening (May 19) in Los Angeles.

The brother-sister duo, who have been with the show for many years, danced while Sia performed her latest single “Elastic Heart.”

PHOTOS: Check out the latest pics of Julianne Hough

Julianne and Derek were joined on stage by a young dancing duo that looked just like them!

Make sure to find out who won this season of Dancing With the Stars.