Julianne Hough will not be returning to 'Dancing With The Stars'.

Julianne Hough

Julianne Hough

The 29-year-old dancer has served as a judge on the popular American celebrity dance competition since 2014 and has competed as a professional on the show five times, but it has now been revealed she won't be rejoining her cast mates for the upcoming 25th season, which kicks off on Monday (18.09.17).

Long time judges Len Goodman, Bruno Tonioli and Carrie Ann Inaba will all be reprising their roles on the panel, and instead of employing a fourth judge full time, the panel will be rounded out by guest judges "wherever possible".

A representative for the show told 'Entertainment Tonight': "We are thrilled to have Len, Bruno and Carrie Ann back in the ballroom and look forward to welcoming guest judges wherever possible."

As of the time of writing, it is unknown why Julianne isn't returning to the show this season, but she has had an action packed summer after tying the knot with her partner Brooks Laich in July.

It is also unknown whether Julianne intends on returning to the show in future seasons, or if this marks her permanent departure from the programme.

Meanwhile, it was recently revealed stars such as Nick and Vanessa Lachey, Sasha Pieterse and Debbie Gibson will take to the dance floor to impress judges this season.

WWE wrestler Nikki Bella, paralympic swimmer Victoria Arlen, actors Frankie Muniz and Jordan Fisher, YouTuber Lindsey Stirling, entrepreneur Barbara Corcoran and NBA player Derek Fisher have also signed up to take part.

'Dancing With the Stars' season 25 celebrity and professional pairings:

Barbara Corcoran with Keo Motsepe

Debbie Gibson with Alan Bersten

Derek Fisher with Sharna Burgess

Drew Scott with Emma Slater

Frankie Muniz with Witney Carson

Jordan Fisher with Lindsay Arnold

Lindsey Stirling with Mark Ballas

Nick Lachey with Peta Murgatroyd

Nikki Bella with Artem Chigvintsev

Sasha Pieterse with Gleb Savchenko

Terrell Owens with Cheryl Burke

Vanessa Lachey with Maksim Chmerkovskiy

Victoria Arlen with Val Chmerkovskiy