Kerber avenged her defeat against Williams in the 2016 Wimbledon title match, overwhelming the seven-time champion with a stunning 65-minute upset on Centre Court.
"I knew I had to play my best tennis against a champion like Serena," Kerber said.
"It was my second chance to play in the final. I think I'm the next one after Steffi who won. That's amazing."
Williams had hoped to equal Margaret Court's record of 24 Grand Slam singles titles by winning her first major prize since becoming a mother in September.
The 36-year-old, who last won a Grand Slam at the 2017 Australian Open, went into the final as the title favourite, even though she was playing only the fourth tournament of her post-pregnancy comeback.
But instead world number 10 Kerber sprang a huge surprise, making her Germany's first female champion at the All England Club since Steffi Graf in 1996
