Harry Styles.
Mick Jagger has taken the One Direction heartthrob under his wing.Getty: ANDREW COWIE

As if his life couldn't get any better as part of the biggest boy band on the planet, One Direction heartthrob Harry Styles has reportedly made friends with a rock legend.

The 20-year-old star is said to be 'thrilled' after striking up an unlikely friendship with his idol and fellow Brit, Mick Jagger.

According to the Sun, the Little Things hitmaker, who found fame on the X factor alongside bandmates Niall Horan, Zayn Malik, Liam Payne and Louis Tomlinson, has grown close to the Rolling Stones rock star in recent weeks.

Jagger, 71, reportedly took Styles under his wing after taking a shine to him at a Rolling Stones party.

"Harry made it clear he was a huge fan of Mick but never expected he'd take any notice. But people kept telling Mick how much Harry looked like a younger version of him so he started to investigate One Direction," an insider said.

"Mick's not a massive fan of their music because he's a rocker to the core, but he thinks they're lovely young lads and took a shine to Harry.

"He invited him to a special party during the Stones' tour and they instantly hit it off."

And Styles feels like he has won the jackpot with his new friend, who he is often compared to.

"They swapped numbers and now regularly phone each other just to chat. Harry can't believe it," the source adds.

"It's very much a friendship. Mick isn't trying to be a mentor or anything like that, which is why Harry likes him so much."

Meanwhile, The Rolling Stones are preparing to fly to Australia to resume their world tour, after the series of gigs were put on hold following the death of Jagger's girlfriend L'Wren Scott in March.