The seventh seed will take on Serena Williams - who is one win away from equalling a grand slam record - on Saturday after a fine display to beat Elina Svitolina 6-1, 6-3 in just an hour and 13 minutes.
She is the first Romanian woman to make the singles showpiece at the All England Club.
Meanwhile, Williams overpowered unseeded Czech Barbora Strýcová 6-1, 6-2 in 59 punishing minutes on Centre Court and is now close to a 24th grand slam singles title.
Speaking to the BBC after walking off Centre Court, following her win, Halep said: "It is an amazing feeling. I am very excited and nervous. It was one of the best moments of my life."
It will be Halep's fifth grand slam final and comes just over a year after she won her first major title at the fourth attempt at the French Open.
It was a particularly proud moment for the 27-year-old's mother Tania, with Halep saying: "I talked to my mum after the match. About 10, 15 years ago she said her dream is (for Halep) to play the final in Wimbledon because everyone is here, the Royal Box.
"So today her dream came true. I will play a final. It's very special this moment. To be able to play Wimbledon final, it's pretty amazing. I will enjoy for sure."
Halep has only won one of her previous 10 matches against Williams, but few have been one-sided and their fourth-round clash at the Australian Open in January was one of the best of the year.
"I played many matches against her," she said.
"Many of them were very close. Now, if I face her, I will believe that I have my chance to win.
"Of course, I respect a lot what she has done and what she's doing. But now I feel stronger mentally facing her. It's just a big challenge for me."
World number seven Halep, who was number one this time last year, will face the seven-time champion determined to equal Margaret Court's record tally of Grand Slams.
Failure to match Court weighed heavily on Williams in her defeats in last year's Wimbledon and US Open finals - but the 37-year-old means business this year, having upped her levels round by round to march into her 11th final at the All England Club.