A panel comprising members from the Mountain Bike Australia Board chose the winning event.
The Dwellingup 100, which is the largest of its kind in WA, became part of the National Cross Country Marathon (XCM) Series in 2015.
The 2015 event featured four distances – 100km, 40km, 14km and the new 64km, with more than 1000 riders taking part.
Event director Dave Budge said winning the award was a fantastic achievement given hundreds of mountain bike events are run each year in Australia.
“The mountain biking calendar in Australia is jam-packed with a multitude of events, so we’re very proud to have been voted Australia’s best event by the national body,” he said.
“We’ve been lucky over the years to hold the event in Dwellingup, which is such a beautiful part of WA. We’re excited to deliver the 2016 event and hope that the national recognition attracts even more riders from WA and interstate.”
This year’s D100 is on Saturday, September 3, at Dwellingup Football Oval.
Online registrations will open at the end of April.