Hegesippus was a Christian writer of the second century CE, often called Hegesippus of Palestine or the Nazarene. This suggests he likely came from a Jewish-Christian background in the eastern Roman Empire. According to the later church historian Eusebius, Hegesippus lived during the time of several early bishops of Rome and traveled there, recording a list of its bishops. Eusebius considered him part of the first generation of Christian leaders after the apostles. Hegesippus also traveled to other churches, like the one in Corinth, to verify they were teaching what he considered correct doctrine, showing his concern about emerging alternative teachings.

He is known for a single major work, now lost, titled the Hypomnēmata (often translated as Memoirs or Memoranda). It was a five-book treatise written to defend orthodox Christian beliefs. Some scholars also refer to it as an early form of church history.

Hegesippus is a significant source for early church history because of his early date. His work is considered one of the first attempts to record the history of the Christian church. Eusebius relied on Hegesippus's accounts for key information, such as the story of James the Just (the brother of Jesus) and the succession of early bishops. Modern scholars see his fragments as a valuable window into the concerns of second-century Jewish-Christian communities as they worked to define their traditions against other interpretations.