Numenius of Apamea was a Greek philosopher active in the 2nd century CE during the Roman era. He was a Platonist from the city of Apamea in Syria, working in the period known as Middle Platonism. Beyond this, the specific details of his life and education are not recorded in surviving sources.

His philosophical writings survive only in fragments, quoted by later Neoplatonist and Christian authors. His known works include On the Good, On the Incorruptibility of the Soul, and On the Secrets in Plato, alongside other treatises on topics like numbers and place. He also wrote a dialogue called The Hoopoe and a work Against the Gnostics is attributed to him, though the content of these is largely lost.

Numenius is a significant figure for his syncretic approach to philosophy. According to modern scholars, he sought to harmonize the teachings of Plato with those of Pythagoras and engaged with other wisdom traditions. His metaphysical system introduced a hierarchy of divine principles, featuring a supreme First God and a creative Second God responsible for the world. This framework is seen as an important precursor to the later developments of Neoplatonism. His allegorical interpretations and ideas were extensively debated and cited by major later thinkers, including Plotinus, Porphyry, and several early Christian writers.