LOUISA Johnson, the youngest ever winner of the X Factor, has been named as special guest at pop superstar Olly Murs’ outdoor concert at the historic Powderham Castle, near Exeter on Saturday, July 29.

The 19-year-old starlet won the 2015 series of the TV talent show at the age of 17 with Simon Cowell calling her ‘the best singer he had ever seen on the show’.

She has since had hits with the songs Forever Young and So Good and featured on the Clean Bandit top five single Tears.

R’n’B and pop star Louisa performed last year to 80,000 fans at Wembley Stadium with the likes of Ariana Grande and Little Mix. Her debut album is due out this year.

Thousands of fans are expected to descend on Powderham Castle – home of the Earl and Countess of Devon – for the concert with Olly, who played to more than 20,000 people at the venue in 2013.

Louisa said: ’I’m delighted to be appearing with Olly at Powderham. He has always been one of my heroes and to be sharing a stage with him will be a very special moment.

’Little did I dream that when I was watching him on the X Factor I would one day win the competition myself and end up performing with him.’

Olly, 32, shot to fame on the X Factor in 2009 finishing second to Joe McElderry with Stacey Solomon third.

Popular singer-songwriter Olly is one of British music’s biggest stars with record sales exceeding 10 million.

He scored an amazing fourth consecutive number one album with his latest, most personal offering 24 Hrs. His top singles include Dance With Me Tonight, Troublemaker, Heart Skips A Beat and Dear Darlin’.