Stephen John Port was born on February 22, 1975, in Southend-on-Sea, Essex, England. When he was one year old, his family moved to Dagenham, East London. Port grew up in Dagenham, where his parents still live. He was often described as a "loner" during his early years. At school, he faced bullying and was known for his quiet personality. Some former teachers noted that he did not engage much with others.

Port’s neighbors remarked that he had a peculiar and childlike personality. Even as an adult, he showed odd behavior, such as playing with children's toys. After finishing school at the age of 16, he attempted to go to art college. However, the cost of classes was too high for his family. Instead, he spent two years training to become a chef.

In his mid-twenties, Port came out as gay. He lived with his parents until his early thirties. After that, he moved into a flat in Barking, London. During this time, he worked as a chef at a Stagecoach bus depot in West Ham. Port had a brief appearance on an episode of the television show MasterChef. At that time, he was noted for having an athletic look because he regularly visited the gym.

Port was bald and chose to wear a blond wig when he was out in public. He felt that the hairpiece increased his confidence when meeting other men. Various individuals who knew him described his personality as childish, which led to some relationships ending.

Stephen John Port is a serial killer who committed his crimes between 2014 and 2015. He met his victims through online gay and bisexual social networks and dating apps. Port created fake biographies to attract young men, claiming to have graduated from Oxford University and served in the Royal Navy. He used a drug called gamma-hydroxybutyric acid (GHB), which is often associated with date rape, to drug his victims.

Port's first known victim was Anthony Walgate, a 23-year-old fashion student. Port contacted Walgate pretending to be a client. After drugging him with GHB in his flat, Port raped him and then gave him an overdose of the drug, causing Walgate's death. The next day, Port placed Walgate's body outside his flat and made an anonymous call to emergency services.

Over the next year, Port killed three more men: Gabriel Kovari, 22, Daniel Whitworth, 21, and Jack Taylor, 25. Kovari had briefly lived with Port. Whitworth’s body was found in a graveyard, with a fake suicide note nearby that suggested he had killed Kovari and taken his own life out of guilt. Taylor was found nearby, also in similar circumstances.

Authorities eventually found the bodies of three victims in or near the graveyard of St Margaret’s Church in Barking, while Walgate's body was outside Port's flat. Port was later arrested and charged with murder and multiple counts of rape and sexual assault. In total, he was found guilty of killing four young men and assaulting others.

In 2016, Port was convicted and given a whole life sentence. Following his conviction, there were concerns regarding police failings in their investigations of the initial cases. Families of the victims received compensation from the Metropolitan Police due to mishandling of the inquiries. The handling of the case was re-examined and investigated further after Port's arrest, raising questions about how the authorities missed important connections between the deaths.