Joe Jonas' Fantasy has become a reality - he will be supporting Britney Spears on tour.

The middle Jonas brother had posters of the superstar on his wall, and readily admits to having a childhood crush on her.

Now he has announced that he will open the European leg of her Femme Fatale tour from October 16.

"It's a dream come true," he told People.

"She was the first girl I ever had a poster on my wall of, and her album was the first CD I ever bought."

Joe – who is promoting his upcoming solo album Fastlife – added: "It's so funny to think I had that on my wall and here I am about to perform with her."

He later tweeted: "It's official. Performing on the European leg of @britneyspears tour."

The 21-year-old singer described Britney, whom he first met at an awards show a few years ago, as "a very sweet lady".

He will join the tour on August 5 for one date in the US, before opening 10 shows in Europe.

"I'm really looking forward to being part of this," Joe continued.

"I'll be playing more music than I have the past few times I've performed live so far.

"It's going to be really fun to perform some of my music from the album."

Photo: © Getty