The 23-year-old entered the final day at Golfclub München Eichenried with a three shot advantage but local hero Martin Kaymer carded a stunning 64 to join him at the summit and set the target at 17 under.
After a grinding first 12 holes, Hovland birdied the 13th and 16th to lead by two but a three putt on the penultimate hole left him with just a one shot lead stood on the tee at the par five 18th.
There was no question as to where the trophy was headed, however, as he showed nerves of steel to hit a perfect drive and find the green in two, making a birdie to get to 19 under after a 70.
Hovland has already broken barriers for his country, winning twice on the US PGA Tour and this triumph takes him to a career high 13th on the Official World Golf Ranking.
He also moves into the top ten of the Race to Dubai Rankings in Partnership with Rolex and strengthens his position as he looks to become the first Norwegian to play in the Ryder Cup.
"I grew up watching mostly the European Tour," he said. "There’s a lot of guys who played this week who I grew up watching. It’s cool to be a champion of this Tour, in Germany, in a place that... it’s not in Norway, but it’s close and has some of the same feelings of being home. It’s a huge honour and finally Norway has a win on the European Tour."
He added: "I saw (Kaymer) was creeping up from behind and Jorge was hanging on and after missing a bunch of putts, making the birdie on 13 helped a lot and the par save on 14, that was big for momentum.
"After that, I just tried to play pretty solid golf, not make too many mistakes, I had a three putt on 17 but great birdies on 16 and 18 - it was good enough today.
"It's The Open, Olympics, Ryder Cup, there's so much golf to look forward to and I'm just going to have a blast."
Hovland dropped a shot after missing the green at the par three third but picked it back up as he got up and down from the sand on the fifth and at that point his lead was four after a Campillo bogey on the fourth.
Kaymer had made a bogey on the first but bounced straight back and then left himself three feet at the fifth, before taking advantage of the par five sixth and ninth.
He holed from 11 feet on the tenth, made the most of another par five on the 11th and a tee shot to 15 feet at the 12th meant he was just two back.
Campillo made two putts from the fringe on the sixth and put his tee shot to 11 feet on the eighth to join the group two back as Hovland continued to grind, failing to make the most of the sixth or ninth.
And the leader soon had company as Kaymer holed a 30 footer on the 15th and then drove the 16th and got down in two.
The home favourite then looked to have lost his chance as he missed the green at the 17th for a bogey and found rough off the tee at the par five last, forcing him to lay up.
But he put his third to 13 feet and holed the putt to set the target at 17 under, with Hovland missing another chance as he three putted the 11th for par.
Campillo made no such mistake, taking two putts from 26 feet to get within one of the lead but Hovland broke his run of seven pars with an approach to nine feet at the 13th and he was once again alone at the top.
He left himself a tricky up-and-down for birdie after driving over the back of the par four 16th but played a wonderful shot to leave himself three feet and lead by two with two to play before his bogey birdie finish.
Campillo sandwiched a birdie on the 16th with bogeys on the 15th and 17th as he continued his recent resurgence for a best finish of the 2021 Race to Dubai.
Dubuisson ended both of his nines with an eagle, while also making birdies on the second, third and fifth with bogeys on the fourth and 11th.
Professional debutant Vincent Norrman, South African trio Darren Fichardt, Justin Harding and Shaun Norris, English pair Sam Horsfield and Andy Sullivan, and Austrian Bernd Wiesberger were at 13 under.