Judge Sherilyn Garnett delivered the 41-month sentence for Kenneth Iwamasa, the person who found Perry floating face down and lifeless in a hot tub at his Los Angeles home in October 2023.
Federal prosecutors said Iwamasa injected Perry with ketamine at the actor's request before leaving the residence to run errands.
Perry was dead when Iwamasa returned.
An autopsy report concluded that Perry died from the "acute effects of ketamine," which combined with other factors in causing him to lose consciousness and drown.
Ketamine, a short-acting but potent anaesthetic with hallucinogenic properties, is sometimes prescribed to treat depression and other psychological disorders but has gained popularity as an illicit party drug.
Iwamasa had pleaded guilty to one count of conspiracy to distribute ketamine resulting in death.
As part of a plea agreement, he admitted to repeatedly injecting Perry with ketamine without medical training, including the lethal dose.
Under the deal, he provided key evidence against other defendants.
Prosecutors had asked for at least 41 months in federal prison for Iwamasa, who met Perry in 1992 and had been his live-in assistant since 2022.
They called him Perry's "enabler and drug supplier" in court documents filed ahead of the sentencing.
Iwamasa repeatedly injected Perry throughout October 2023 with ketamine and at least twice found him unconscious but kept administering the drug, they said.
Another time, he saw Perry "freeze" and lost the ability to speak after receiving a ketamine injection from a doctor.
Before his death at age 54, Perry had acknowledged decades of substance abuse that overlapped with the height of his fame playing the sardonic but charming Chandler Bing on the 1990s hit NBC television comedy Friends.
Two doctors, a drug dealer and a go-between who helped obtain ketamine were previously sentenced in the case.
Jasveen Sangha, a dealer dubbed the "Ketamine Queen," received the longest sentence of 15 years in prison.
