Charles Sobhraj was born on April 6, 1944, in Saigon, which was part of French Indochina at the time. His father was Indian, and his mother was Vietnamese. Because Saigon was a French colony, he was eligible for French citizenship. His parents were not married, and his father denied that he was the child's father. When Sobhraj was young, his mother married a French Army lieutenant, who adopted Charles. In 1959, his name was recorded as Charles Gurmukh Sobhraj in church records.

Growing up, Charles felt neglected in his new family, as his stepfather favored his half-siblings. He experienced a turbulent childhood, often moving between Southeast Asia and France with his family. As a teenager, Sobhraj began to get into trouble and committed petty crimes. In 1963, he was arrested for burglary and sent to Poissy prison near Paris. While in prison, he was manipulative and managed to convince prison officials to grant him special privileges, including the ability to have books in his cell. During this time, he met a wealthy young volunteer named Felix d'Escogne and formed a friendship with him.

After his release from prison, Sobhraj moved in with d'Escogne and started mingling with both wealthy socialites and criminals. He quickly developed a taste for the high life and became involved in various scams and burglaries. Around this time, he met Chantal Compagnon, a young woman from a conservative Parisian family. They began a romantic relationship, and Sobhraj proposed marriage to her. However, later that same day, he was arrested for trying to evade police while driving a stolen car. He received an eight-month prison sentence, but Chantal supported him throughout.

Upon his release, Sobhraj married Chantal. By 1970, he had obtained French citizenship through his mother. To avoid arrest, the couple fled France for Asia. They traveled across Eastern Europe using fake documents and continued their life of crime by robbing tourists. In late 1970, they arrived in Bombay, where Chantal gave birth to a daughter named Usha. Sobhraj continued with his criminal activities, engaging in car theft and smuggling operations.

In 1973, Sobhraj was arrested in New Delhi following a failed armed robbery. He managed to escape with Chantal's help by pretending to be ill but was recaptured shortly afterward. After borrowing money from his father for bail, he and Chantal fled to Kabul, where they were again caught robbing tourists. Sobhraj escaped from prison once more by faking illness and drugging a hospital guard. Eventually, he left his family behind and began a life on the run, using multiple stolen identities.

For two years, Sobhraj traveled through various countries, including Turkey and Greece, before getting arrested in Athens with his half-brother André. After a failed escape attempt, he managed to flee, but André was captured and sentenced to 18 years in prison.

On the run, Charles Sobhraj used various methods to finance his lifestyle. He pretended to be a gem salesman or drug dealer to attract tourists. In India, he met Marie-Andrée Leclerc, a tourist from Quebec. She became very devoted to him while ignoring his illegal activities. Sobhraj gathered a group of followers by gaining their trust. He would help them out of tricky situations. In one case, he assisted two former French policemen in retrieving stolen passports that he had taken. In another instance, Sobhraj pretended to help a Frenchman suffering from dysentery but actually poisoned him.

Sobhraj and his accomplice, Ajay Chowdhury, committed their first confirmed murders in 1975. Most of their victims had spent time with them beforehand. Sobhraj claimed that his killings were accidental drug overdoses. However, investigators suspected that he murdered them to prevent them from revealing his crimes. His first victim was Teresa Knowlton, a young woman from Seattle. Her body was later discovered drowned in a tidal pool in Thailand, initially thought to be an accident.

Following Knowlton, Sobhraj killed Vitali Hakim, whose burnt body was found on the road to the Pattaya resort. He also poisoned Dutch students Henk Bintanja and Cornelia Hemker, who were invited to Thailand after meeting Sobhraj. Before the couple could expose him, they were found strangled and burned. The two women connected to these murders earned Sobhraj the nickname "The Bikini Killer" due to their swimwear.

In December 1975, Sobhraj and Leclerc entered Nepal using the passports of their most recent victims. They murdered Canadian Laurent Carrière and American Connie Jo Bronzich soon after. They then returned to Thailand with the victims' passports. Sobhraj's French friends began to suspect him and fled, alerting local authorities.

Sobhraj moved around Asia, committing more murders to acquire passports and evade capture. He killed Israeli scholar Avoni Jacob in Calcutta to obtain his passport. After a brief interrogation by the Thai police, he was released. Investigations into his murders continued, led by Dutch diplomat Herman Knippenberg.

Sobhraj's travels led him to Malaysia, where he murdered Chowdhury, his accomplice, to eliminate a potential threat. By May 1976, authorities in Thailand issued an international arrest warrant after accumulating evidence against him.

Later, Sobhraj formed a new group with two Western women and killed Frenchman Jean-Luc Solomon during a robbery by poisoning him. In July 1976, he tried to drug a group of French students while pretending to be their guide. They overpowered him, leading to his capture. His accomplices confessed, and Sobhraj was charged with Solomon's murder.

He was imprisoned in India for 12 years after a series of trials. In March 1986, he drugged guards and escaped prison but was caught again. He was released in 1997 after most evidence against him was lost. In 2003, Sobhraj returned to Nepal, where he was recognized and arrested while gambling.

On August 20, 2004, he was convicted for the murder of Connie Jo Bronzich and sentenced to life imprisonment. He continued to appeal against his sentence for years. In September 2014, he was convicted of another murder, that of Laurent Carrière, and received an additional 20-year sentence. After undergoing multiple surgeries in 2018, Sobhraj was released due to old age on December 21, 2022, and deported to France.