The 23-year-old saw off 14 other candidates during a selection process that started in July. Each hopeful was put through a series of interviews and exercises at the team's base in Germany, before eight finalists took part in a practical assessment driving the i20 R5 in France.
Hyundai team manager Alain Penasse led the judging panel and said it was a unanimous decision that Huttunen was their man.
"What stood out about Jari was his determination. With only a few starts in an R5 car he had less experience than many of the other candidates, but was immediately competitive and consistent in the i20 R5 on both the tarmac and gravel stages," he explained.
"He is a clearly a very talented driver, and has enormous potential. With the support of the program, we are confident he can continue his rapid progress in the sport next season.”
Huttunen's rally career began in 2013. After two learning seasons on home ground in Finland, he won Germany's Opel Adam Cup in 2016.
He moved to the European Championship in 2017, where he campaigned an R2-spec Opel, and also stepped up to four-wheel-drive R5 competition for the first time. On just his second start in a Skoda Fabia R5 he took victory in WRC 2 at his home round.
As well as tackling a number of WRC 2 rounds in 2018, he will also be offered a programme of tests throughout the season to prepare for each event.
Huttunen said it was "a huge honour" to be selected.
"There were a lot of very talented drivers involved with more experience than me," he explained.
"To be able to draw on the support from such a successful team will allow me to focus fully on my driving and training and continue to improve my performance behind the wheel. Though I only had a short time in the i20 R5 at the test I quickly felt comfortable and was able to push, even in the difficult conditions. Now I can concentrate on preparing over the coming months. I’m really excited for the year ahead.”