The replacement comes shortly after Iggy Azalea, Adam Lambert and Guy Sebastian were announced as the judges for the popular Channel 7 reality show.
Dundas, 33, shared the following tweet celebrating his new role on the show.
In an official statement released on Sunday morning, Jason said 'I'm incredibly humbled and excited to be a part of a show that provides Australians with a platform to live out their dreams as a singer.'
He continued, 'My career as a television host all started from winning a contest, so I know how life changing a show like this can be.'
X Factor Australia also shared their enthusiasm for their new host on Twitter.
Dundas relocated to Sydney from LA in 2014. Since then Dundas has worked as a special correspondent on Entertainment Tonight, interviewing stars like Madonna and Jennifer Anniston.
Dundas is also a brand ambassador for Australian retailer David Jones and even has his own line of men’s active wear.
Luke Jacobz, a former Home and Away star, has hosted The X Factor Australia since 2010. Jacobz has now reportedly moved to LA to pursuit a career in acting.