The British driver, who treated last year's final race in Abu Dhabi as the last of his 17-season career, will team up with Belgian Stoffel Vandoorne for McLaren at the Monte Carlo race on May 28.

Button remains under contract with McLaren after agreeing a two-year ambassadorial role, but he is yet to drive this year's car.

"I'm thrilled to be making a one-off return to Formula One racing, and I couldn't think of a better place to make that return than my adopted home Grand Prix of Monaco," Button said. "I've won the race before, in 2009, and it's one of my all-time favourite racetracks.

"It's a tricky street circuit on which a good driver can really make a difference and, although the McLaren-Honda hasn't begun the season well, I think it may be more suited to Monaco than to the faster circuits that Fernando and Stoffel have raced it on so far this season.

"I realise we won't have a realistic chance of repeating my 2009 victory, but I think we'll have a opportunity to score world championship points, which will be very valuable to the team in terms of constructors' rankings."

Alonso's decision to take part in the 101st Indy 500 left a vacant seat alongside Vandoorne, the Belgian who replaced Button at McLaren this season.

Button, who will start his 306th race in Monte Carlo, was the leading, and obvious, candidate to fill the void.

The Englishman is not scheduled to take part in next week's two-day test here in Bahrain, but despite his recent lack of track action he is hopeful he will prove an able substitute.

"I'm looking forward to pitting myself against the unique racing challenge that is the Monaco Grand Prix," Button, the last driver to win a race for McLaren, added.

"I'll drive the McLaren around Monaco in the simulator beforehand, and I reckon I'll be ready for the race after doing that.

"I'm supremely fit, having done a lot of triathlon training recently, so I have no worries on that score. And it'll be nice to say 'hi' to all my old Formula One mates, too, and hopefully to give the fans something to cheer about."

Button made his debut for Williams back in 2000 before competing in 17 consecutive seasons and racking up more than 300 starts, including 15 victories.

His biggest achievement came in 2009 when he won the championship with Brawn GP, while he became the first team-mate to beat Lewis Hamilton over the course of one season in 2011.

And Eric Boullier, the McLaren racing director, who offered Button the one-off return in Monte Carlo, is delighted the Briton will be back in the car for the sixth round of the championship.

"I was truly delighted when Jenson accepted our suggestion that he race at Monaco instead of Fernando," Boullier said.

"I know I speak on behalf of everyone at McLaren-Honda, and all our sponsor-partners and fans too, when I say that it's great news for Jenson, for McLaren, for Honda, for our sponsor-partners, for Monaco, and for the sport of Formula One.

"Jenson is a class act. He's a superb driver - fast, smooth and precise - and he won't have lost any of his competitive edge over the past few months. After all, he's missed only a handful of grands prix since his last outing in Abu Dhabi in late November last year, and he's as fit as a fiddle. Also, he's always been good at Monaco. He'll do a great job for us, I'm sure of that."

Hamilton led the calls for his former team to bring Button back into the fold here in Bahrain on Thursday.

"I hope Jenson comes back, and it would be great for the sport to have him back in," Hamilton said.

"I like Jenson and he is still one of the best drivers, and his calibre and experience is way ahead of the other drivers able to take that spot, for sure."