Bennani finished second in the race which took place this weekend at Circuito del Jarama, in San Sebastián de los Reyes, north of Madrid.
In total, the Moroccan driver (Audi RS 3 LMS TCR - Comtoyou Racing) secured the title with 285 points, ahead of French John Filippi, who finished second with 257.
Belgian Nicolas Baert came third with 244 points.
Speaking to reporters at the end of the race, Mehdi Bennani said he is "very happy" to win this title after a "very difficult year during which we had bad luck in some races but also we were lucky in others", while congratulating his team for the excellent work carried out.
"I am proud to win TCR Europe, especially with the difficulties triggered by the coronavirus with regard to travel and tests," he added.