It was Kerber’s third title at the majors to add to her Australian Open and US Open triumphs in 2016.
Williams, 36, had been attempting to win a first Grand Slam since giving birth to her daughter Olympia in September.
Kerber is the first German woman to win the Wimbledon title since Steffi Graf in 1996.
After a controversially delayed start she defended her baseline brilliantly to extract 24 unforced errors from an often wayward Williams and clinch her third Grand Slam title.
She remained ice cool at the end and held her nerve, providing another coaching triumph for Belgian Wim Fissette, who this time last year oversaw the run of Jo Konta to the last four.
For Williams, faced with a resolute opponent, winning four matches in six days looked beyond her at this stage of the return following the birth of her daughter.
Kerber has shown before that she is not afraid of Williams, notably in the 2016 Australian Open when she caused a shock by winning in three sets. She also put up a strong showing in their 2016 SW19 final.