The 27-year-old seventh seed, who was French Open champion in 2018, will be playing in her fifth Grand Slam final.
"It's an amazing feeling but I am also excited and nervous. It is one of the best moments of my life," said Halep.
"The match was not easy, the games were long and went deep.
"I fought hard to win this match and I was strong mentally and physically and had the right tactics."
Halep will face either seven-time champion Serena Williams or unseeded Barbora Strycova of the Czech Republic for the title on Saturday.
Halep, who had knocked out new star, 15-year-old Coco Gauff in the last 16, lost in her previous semi-final appearance at Wimbledon to Eugenie Bouchard in 2014.
However, she said she was a different player now and had taken to grass.
"I have more experience, I don't give up anymore. I plan to be the best version of myself and fight to the end." she said.
The easy manner in which former world number one Halep wrapped up the match had not looked on the cards at the outset.
Svitolina, the first Ukrainian woman to reach a Grand Slam semi-final, and Halep traded shots aplenty and break points in the opening two games which took over 20 minutes to complete but Halep emerged on top with a 2-0 lead.
Svitolina, being watched from the players box by her English coach Andy Bettles and French boyfriend and ATP star Gael Monfils, briefly raised her game to break back.
However, Halep broke again immediately and 24-year-old Svitolina gave an indication of her increasing frustration when she netted a simple volley and lashed out, kicking the ball into the net.
Worse was to come for Svitolina on her next service game wheh Halep produced a stunning shot to go 5-1.
The 27-year-old Romanian dashed across court to get to Svitolina's drop shot and flashed it cross court.
Halep, who had not faced a seeded player until Svitolina, faced some resistance as she served for the set eventually taking it on her sixth set point.
Although Svitolina stayed with Halep for the first part of the second set, the self-belief and fight had gone and when the Romanian broke for 4-3 it was game over.
All that was left was for Haelp to raise her arms in the air and her eyes to the sky blowing a kiss a the same time.