Mohammad Jafar Pooyandeh is an Iranian translator, writer and sociologist who was killed by agents of the Iranian Ministry of Intelligence as part of the Chain Murders in the 1990s. The Chain Murders were a series of political assassinations, carried out between 1988 and 1998 by the Iranian government, against Iranian academics and critics of the Islamic Republic.

Pooyandeh, who had worked in the Office of Iranian Cultural Studies and was also an active member of the Iranian Writers' Association, was killed on December 9, 1998.

He was a supporter of left-wing Iranian politics – though he did not follow traditional Marxist ideology and never joined a political organization or political party. Pooyandeh was a staunch defender of democracy, human rights and the freedom of thought and expression.

Pooyandeh graduated from high school in 1970 and was accepted to study Criminal Law as an undergraduate at the University of Tehran later that year.

In 1974, Pooyandeh went to the prestigious Sorbonne University in France, where he continued his studies and received a master's degree in sociology.

After the Islamic Revolution in 1979, Pooyandeh devoted most of his time to translating philosophical and literary works from French into Persian. A number of these translations have yet to be published. 

A month before Pooyandeh was killed, the ceiling of the room he was renting collapsed and his work desk and books were buried under the rubble.

In a foreword to the Persian translation of György Lukács’ book History and Class Consciousness, Pooyandeh describes the economic pressures in his life, writing: “I continued to translate the book History and Class Consciousness at the height of all kinds of class-related economic pressures and in the worst material and psychological conditions. Perhaps it was these pressures that motivated me to complete the translation of this book, and what better consolation than translating one of the world's most important books into Persian, in recognition of the contemporary world and its class oppressions, whether or not it is accepted or given its due consideration.”

Mohammad Jafar Pooyandeh left his home on December 9, 1998, never to return. Ten days later his body was found in Badamak village in Shahriar city.

The Forensic Medicine Organization of Iran announced that the cause of Pooyandeh’s death had been asphyxiation. It was later revealed that he had been one of a victim of a political assassination: one of the Chain Murders carried out by agents of Iran's Ministry of Intelligence.

Ali Roshani was later identified as the person who strangled Pooyandeh. He was eventually sentenced to life in prison. But it was never clear whether Roshani was transferred to prison to serve his sentence. 

Mohammad Jafar Pooyandeh was buried in the Emamzadeh Taher Cemetery in Karaj. His published works include 26 books and articles concerning sociology and philosophy.