Ronnie writes in his forthcoming memoir that he was just 17 years old when the tragic incident took place.
"Stephanie de Court was my childhood sweetheart. It was all very innocent - talking, holding hands after school, the occasional kiss," Contactmusic quoted him as writing in the book.
"On May 31, 1964, Stephanie and some girlfriends were coming to see my band play but were killed in a car crash on the way. Stephanie's parents didn't want me at the funeral," he writes.
The rock star has revealed that he started drinking only to forget the painful memories of his love.
"Some friends took me to the pub and got me drunk because it was the only way I could accept the fact that she was gone from my life forever. In the bottle I discovered a way not to think about it," he writes in the book.