Playing in only her second grand slam event since she nearly lost her life after giving birth 10 months ago, the American struck 16 winners and just seven unforced errors as she defeated the 13th-seeded German 6-2 6-4 on Centre Court.
Williams, 36, faces former top-ranked Angelique Kerber in the final as she bids for an eighth Wimbledon title to tie Australian Margaret Court's all-time record of 24 grand slam singles titles.
Germany's Kerber dominated former French Open winner Jelena Ostapenko of Latvia in the other semifinal. In the 2016 Wimbledon final, Williams beat Kerber in straight sets.
"It's crazy, I don't even know how to feel, because I literally didn't expect to do this well in my fourth tournament back," Williams said in a televised interview.
Williams, who gave birth to a baby girl, Alexis Olympia, in September, added: "I had a really tough delivery, I had to have multiple surgeries, and almost didn't make it to be honest.
"I remember, I couldn't even walk to my mailbox. It's definitely not normal for me to be back in the Wimbledon finals. I'm taking everything as it is and just enjoying every moment."
Williams, the world No. 181 who was given a protected seeding of No. 25 by tournament organizers due to her pedigree, is two titles shy of Martina Navratilova's all-time women's singles record at the All England Club.
Earlier, Kerber neutralized the booming groundstrokes of Ostapenko to reach her second Wimbledon final.
The former top-ranked German didn't drop a set against the Latvian, winning 6-3 6-3 in 68 minutes on Centre Court.
"She's clearly a really good grasscourt player, and she's been going in the draw really well," said Williams about Kerber, whom she leads 6-2.
"I've been watching her matches. I love watching her play and I'll get to play her now. Whatever happens, honestly, it's an incredible effort for me and just good motivation to keep going for the rest of my career."
Kerber, who beat Williams in the final of the 2016 Australian Open, is ready for a tough match.
"I know that I have to play my best, best tennis to beat her, especially on the grass, on the Centre Court, where she won so many titles here," Kerber, a two-time grand slam winner, said in a news conference.
After last week's "Seedageddon," which had robbed the tournament of all of its top-10 seeds, order was restored in the latter stages of the tournament, with three former grand slam winners advancing to the last four.
The odd one out in the semifinals had been Goerges, a late bloomer who was playing in her first major semifinal at the age of 29.
Three years ago, Goerges had completely overhauled her coaching setup and moved from northern Germany to southern Germany in an attempt to kick start her stalling tennis career.
Although she had reached the semifinals having hit more winners (199) and aces (44) than any other woman in the draw, she had no answer to the aggressive game style of Williams, who had also beaten her in straight sets at Roland Garros last month.
Having saved a break point in her opening service game, Goerges got broken in her second service game as Williams attacked.
Thumping ground strokes and firing off booming serves, Williams rushed to a 5-2 lead, and took the first set in 33 minutes as she broke her opponent for a second time.
Having just made four unforced errors in the first set, Williams continued to impose herself on Goerges in the second as she stood close to the baseline to get the first strike in.
Just like in the first set, Williams broke for a 4-2 lead in the second, this time on a drop shot error by her opponent.
Playing in just the 13th match of her comeback, and facing her first top 50 opponent at Wimbledon, Williams wavered as she got broken while serving for the final at 5-3 on a blistering forehand.
The American responded straight away, breaking serve and taking the match in the next game when a lob sailed long.
"I just feel that when I don't have anything to lose, I can just play so free, and that's kind of what I am doing," said Williams.
It wasn't that Goerges, who had 20 winners and made just 11 unforced errors, played badly.
"The first set we played 40 minutes for 6-2. I think every single game was very close," said Georges, who insisted she would leave Wimbledon "with my head held up high" after losing in the opening round five years in a row.
Kerber, one of the best defenders in the women's game, had stifled Ostapenko's attacking game, as she won the match hitting 10 winners and making just seven unforced errors.
The erratic Ostapenko, who put up a fight in the final stages of the match, produced 30 winners but was eventually undone by 36 unforced errors.
A ferocious ball-striker, the 21-year-old Ostapenko stunned the tennis world last year when she beat title favorite Simona Halep from a set and a break down to become the first unseeded player in the Open era to win the Roland Garros title.
After a breakthrough 2016, during which she won the Australian Open and US Open and rose to No. 1 in the world, Kerber struggled with the weight of expectation in 2017, as she dropped out of the top 20 for the first time in five years.
In November, Kerber announced she had parted ways with her long-time coach, Torben Beltz, and hired Wim Fissette, the Belgian who used to guide former world No. 1 Kim Clijsters.
The change paid off, with Kerber now playing for the Wimbledon title after a quarterfinal spot at Roland nGarros last month and a semifinal place at the Australian Open at the start of the season.
"With Wim, with fitness coaches, some physios, my whole team, I think they helped me good to coming back, to really believe in me again," Kerber said.