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.