Williams took just 79 minutes to blitz Sharapova off Centre Court with 13 aces and 29 winners as the five-time Wimbledon champion secured her 18th career win in 20 meetings with her bitter rival.
The 33-year-old American will face Spanish 20th seed Garbine Muguruza on Saturday in her first Wimbledon final since 2012. It will be her 25th Grand Slam final as she eyes a 21st major title.
"I got a little nervous because it was the semi-finals and it's a long time since I've been this far at Wimbledon. I'm excited to get through," said Williams, who didn't allow Sharapova a single break point.
"It wasn't easy out there, but when she stepped up her game I was able to step up mine. The feeling gets better. It's been a long time since I've been in the final here. It's really cool."
Serena, who extended her winning run at Grand Slams to 27 matches and her 2015 record to 38-1, is just one win away from holding all four major titles at the same time - a feat she last achieved in 2002-03.
She is also within touching distance of becoming the first woman to win the French Open and Wimbledon back to back since she last achieved that difficult double in 2002.
And, adding to the wealth of historic milestones in her sights, Serena remains in the hunt to be the first woman since Steffi Graf in 1988 to win a calendar Grand Slam.
It was another chastening defeat for Sharapova and, although the Russian world number four is due to return to number two in the rankings next week, the latest instalment of their one-sided rivalry provided further proof of the vast gulf in class.
It was at Wimbledon where the roots of their rivalry took hold in 2004 when Sharapova, then aged just 17, shocked Serena in the final.
Their relationship has since turned increasingly frosty, with both players publicly sniping about Sharapova dating Serena's old boyfriend, the Bulgarian player Grigor Dimitrov.
Sharapova had to go back 11 years to recall her last success against Williams and had won only one set in their last 12 encounters, even losing her sense of superiority at Wimbledon, where Serena had thrashed her for the loss of just one game in the 2012 Olympic final.
The American had already deprived Sharapova of a major title this year in the Australian Open final, and it quickly became apparent there would be no change to the now familiar plot.
Sharapova, in her fifth Wimbledon semi-final and her first since 2011, struggled to even get her service action right in the first game of the match. With her ball toss causing problems, the Russian served three double faults to hand Williams a crucial early break.
The American hardly needed the gift, but she gratefully accepted it anyway, turning to her lethal serve to batter down a succession of aces and establish a 3-1 lead.
Sharapova still hadn't shaken off the nerves on her serve and Serena made her pay in the fifth game, reading the Russian's deliveries perfectly and punishing them with ground-strokes too deep and powerful to stop.
The five-time Grand Slam champion seemed to meekly accept her fate and the usually demonstrative Serena, who muscled her way to the decisive break in the fifth game in the second game, was tested so little that she barely bothered to celebrate once the job was done.