The Frenchman had already wrapped up the World Championship during round 16 in the Netherlands, but secured his eighth win of the season to increase his impressive points lead.
Although the dominant Febvre had already taken the title from defending champion Antonio Cairoli, to become the first man since the Italian to win as a rookie, there were still podium places up for grabs at the 18th and final round in Glen Helen.
Another French rider, Gautier Paulin took second overall, while Russian Evgeny Bobryshev finished third. Britain’s Shaun Simpson landed his first ever top five finish in fourth, one place ahead of Jeremy Van Horebeek.
"I am so pumped to win," he said. "It's been an amazing year for me. I cannot thank my team enough, they did a great job. Now we are working for the Nations and we'll go again next year."
In the MX2 Classification the race for the world title came right down to the wire with Tim Gajser of Slovenia lifting the title on the last day, despite American Jessy Nelson winning on home soil.
There is still one more event to go this season as the world’s best riders head to France for the Motocross of Nations with Febvre and Paulin looking to lead the home team to victory this weekend.