The 22-year-old dominated the three-week race, taking victory after the 21st and final stage won by Colombian Juan Sebastian Molano.
Quick Step rider Evenepoel is the first Belgian to win a Grand Tour since Johan De Muynck's triumph in the Giro d'Italia in 1978. "It's history for my team, for my country and for myself.
We can be really proud of what we did the last three weeks," Evenepoel said at the finish line. "It's sinking in now, yesterday I already felt it, but it's official now." Behind Evenepoel, Spaniards rounded out the podium with Movistar's Enric Mas second at 2min 05sec and 19-year-old Juan Ayuso of UAE Emirates third at 4min 57sec after 3,280km of racing.
This was a career landmark for Evenepoel and concludes his comeback from a career-threatening fall into a ravine during the Tour of Lombardy in Italy two years ago.