"This has been the most amazing experience ever. ... Thank you so much," Johnson said upon learning she and her partner Mark Ballas had won.
Host Tom Bergeron said this season's competition was the closest ever with less than 1 percent of the final tally separating Johnson and Ballas from runner-up couple Marini and Cheryl Burke.
The winner was determined by combining two night's scores from the show's judges, as well as viewers' votes.
Celebrity Families of 2014 [PHOTOS]