Getty spent most of his childhood in Rome, Italy, while his father headed the Italian division of the Getty family's oil Business. His parents divorced in 1964 when he was eight years old, and his father remarried in 1966 to model and Actress Talitha Pol. The family adopted a hippie lifestyle, spending much time in Britain and Morocco during the 1960s. Getty remained in Rome living with his mother Gail and attended St. George's British International School. In early 1972, he was expelled from St. George's after painting offensive six-feet-high wording aimed at the school's headmaster in a hallway of the school. Later that year, his stepmother died of a heroin overdose in Rome. While his father moved back to the United Kingdom, Paul remained in Italy where he lived a bohemian lifestyle, frequenting nightclubs and taking part in left-wing demonstrations. Endowed with considerable artistic talent, he reportedly earned a living making jewelry, selling paintings, and appearing as an extra in movies. The Italian magazine "Playmen" paid Getty $1,000 to appear in a naked spread and on the cover of its August 1973 issue, released a month after he was kidnapped.

Getty III was found alive in a petrol station of Lauria, in the province of Potenza, on 15 December 1973, shortly after the ransom was paid. At his mother's suggestion, he called his grandfather to thank him for paying the ransom, but J. Paul Getty refused to come to the phone.

In 1974, Getty married German national Gisela Martine Zacher (née Schmidt), who was five months pregnant. He had known her and her twin sister Jutta since before his kidnapping. Getty was 18 years old when his son, Balthazar, was born in 1975. The couple divorced in 1993.

Permanently affected by his kidnapping, Getty suffered from drug and alcohol addiction during the years that followed. In 1981, he drank a Valium, methadone, and alcohol cocktail which caused liver failure and a stroke, leaving him quadriplegic, partially blind and unable to speak. Afterwards, he was taken care of by his mother. He eventually sued his father for $28,000 a month to cover his medical needs. He never fully recovered and remained severely handicapped for the rest of his life. By 1987, however, he was able to regain some degree of autonomy. He could again visit concerts and movies and was even able to ski when strapped to a metal frame.

The 1995 book Painfully Rich: the Outrageous Fortunes and Misfortunes of the Heirs of J. Paul Getty by John Pearson includes significant content on Getty's kidnapping ordeal. The book was adapted to the 2017 film All the Money in the World, directed by Ridley Scott. John Paul Getty III is played by Charlie Plummer and, as a young boy, by Charlie Shotwell.

In 1999, Getty, along with several other members of his family, became citizens of Ireland in return for Investments in that country of approximately £1 million each, under a law which has since been repealed.

On 5 February 2011, aged 54, Getty died at Wormsley, Buckinghamshire, following a long illness. He had been in poor health since his 1981 drug overdose. He was survived by his son and his mother.

Nine of the kidnappers were apprehended, including a carpenter, a hospital orderly, an ex-con, and an olive-oil dealer from Calabria, as well as high-ranking members of the 'Ndrangheta—a Mafia organization in Calabria—Girolamo Piromalli and Saverio Mammoliti. Two were convicted and sent to prison; the others, including the 'Ndrangheta bosses, were acquitted for lack of evidence. Most of the ransom money was never recovered. In 1977, Getty had an operation to rebuild the ear that had been cut off by his kidnappers.

After young Paul's ear was cut off, Getty Sr. negotiated a deal to get his grandson back for about $2.9 million (equivalent to $16 million in 2017). Getty Sr. paid $2.2 million—the maximum amount that was tax deductible—and lent the remainder to his son, who was responsible for repaying the sum at 4% interest.

The kidnapping is also dramatized in the 2018 television series Trust, directed by Danny Boyle, with Harris Dickinson as John Paul Getty III.