Harry Potter, Indiana Jones, James Bond and Rocky Balboa aren’t just fictional creations — they were all inspired by real people.

Rocky Balboa: The inspiration for Sylvester Stallone’s fictional character was a real-life journeyman boxer named Chuck Wepner.

Stallone went to see Wepner fight Muhammad Ali. The “Bayonne Bleeder,” as he was known, was a 20-to-1 underdog and Ali predicted he’d knock him out in three rounds.

But in true Rocky fashion, the slugger made the most of his one chance at fame. He actually knocked Ali to the canvas in the 9th round. Ali got up, but he still wasn’t able to put his opponent away. Although Ali won, the fight went the distance.

“For one brief moment, this supposed stumblebum turned out to be magnificent,” said Stallone. “I said: Boy, if this isn’t a metaphor for life. His entire life crystallized at that moment.”

While Sly put pen to paper and found fame, Wepner slid back into obscurity. He continued to get into brawls — in bars — and now makes his living as a liquor salesman.

Dracula: Author Bram Stoker based his famous blood-sucking count on a 15th-century Romanian warlord named Prince Vlad III (inset), who is estimated to have slaughtered as many as 100,000 people. He drank the blood of some of his victims.

The cruel prince was known as Vlad The Impaler because of his habit of impaling people, including children, atop sharpened poles to die.

He was also called Dracula. Drac is a Romanian word for dragon or devil and Dracula means son of a devil.

And he lived in a castle in a part of Romania known as . . . Transylvania!

James Bond: Author Ian Fleming patterned 007 after Dusko Popov, a Yugoslavian playboy agent nicknamed Tricycle because he liked three-in-a-bed sex.

Fleming worked in British naval intelligence during World War II and was detailed to trail the charismatic spy, who was eventually recruited to work as a double agent for the British.

Popov was known for his irresistible charm and his superb work as a spy. In fact, he could have changed the course of the war. He discovered Japan’s plans to attack Pearl Harbor months before it happened, but his report fell on deaf ears.

Sherlock Holmes: Arthur Conan Doyle’s detective was inspired by a professor the author had at Scotland’s Edinburgh University while he was studying to be a doctor — Dr. Joseph Bell, who was also Queen Victoria’s personal physician.

Bell, with his sharp angular nose and chin and long sensitive fingers, was a widely read poet, raconteur, sportsman, naturalist and bird-watcher.

But it was his genius at diagnosing patients that caught Doyle’s attention.

Young Doyle would follow Bell as he made his rounds at hospitals, dazzling students with his ability to deduce facts, both medical and personal, just from observation. For instance, he noted the soft hands and brawny arms of a woman and correctly deduced that she worked as a laundress.

According to Bell’s great-granddaughter, Mrs. Barbara Craig: “It was his teaching gimmick that made Doyle think up Sherlock Holmes. For instance, he used to say to his students, when a patient came in, ‘Now what can you tell us just by observing?'”

Harry Potter: Author J.K. Rowling based her fictional wizard on a boy she grew up with in England — Ian Potter, now a 35-year-old father of two.

“A gang of children, including myself and my sister, used to play together. Two of our gang members were a brother and sister whose surname was Potter,” said Rowling.

Ian’s sister Vikki said: “Ian was the perfect inspiration for a wizard. He was a nightmare, forever playing tricks. He had this thing about slugs. When we had picnics, he was always hiding slugs on plates. But our favorite thing was to dress up as witches.”

Indiana Jones: The whip-wielding hero was based on a 19th-century Italian archaeologist named Giovanni Battista Belzoni.

Standing 6-foot-7, Belzoni had been a circus strongman before turning to archaeology.

Although he never found the lost ark, he did make a number of spectacular finds. But Egyptologists still shake their heads in dismay at his cavalier ways. One time he tore down an ancient wall just to see what was beyond it.

Like the movie character — whose archenemy was Belloq, the French villain in “Raiders” — Belzoni had a French rival who was also looking for priceless artifacts.

Belzoni was once ambushed and trapped by a band of Arab henchmen who’d been hired by his rival, but the Italian giant was able to make good his escape in true Indiana Jones style.

Norman Bates: A real-life psycho named Ed Gein was the inspiration for the creepy killer in director Alfred Hitchcock’s classic movie “Psycho.”

When cops went to Gein’s isolated farmhouse in Wisconsin in 1957 to check on the disappearance of a number of women, they made some grisly discoveries.

Gein had turned the upstairs into a shrine to his dead mother. Downstairs, cops found the headless body of a woman hanging upside-down from a beam. Lamp shades and baskets had been made out of human skin. A belt was made from nipples, four noses and a heart. An armchair was covered entirely with human skin.

Gein was judged insane and eventually died in a mental institution.

He was also the basis for another fictional killer — Buffalo Bill in “The Silence of the Lambs.” Like Ed, Bill skinned his women victims and used their flesh as clothing.