Mycenaean religion means the religion of mainland Greece in the Late Helladic (LH) period, when we know from the evidence of Linear B that the language of administration was Greek. The principal centers in this period are Mycenae and Pylos in the Peloponnese, Thebes in Boeotia, and Knossos in Crete, which Greeks must have taken over sometime around 1400 bce. Our picture of Greek civilization in this period is still incomplete; above all, we do not know whether there was a single center of power, or if so, where it was (Mycenae and Thebes are the likely contenders). Hittite records from the fourteenth and thirteenth centuries refer to Ahhiyawa, which is now generally identified with Mycenaean Greece.

Research on Mycenaean religion can be divided into two phases, before and after the decipherment of Linear B in 1952. The most comprehensive survey of the archaeological and iconographical sources was by Martin Nilsson, who argued for a unified Mycenaean/Minoan religion, which was a distant ancestor of the Greek religion of the alphabetic period. The decipherment of Linear B as Greek enabled scholars to explore in a more focused way the relationship of Mycenaean religion to the religion of the Minoans (whose language was not Greek; see discussion of Mycenaean religion and Minoan religion) and to Greek religion of the alphabetic period (see discussion of Mycenae and Greek religion of the alphabetic period). Archaeological excavations in the last fifty years have also been important, for example, at the Cult-Center at Mycenae (see discussion of cult places) and at Phylakopi on the Aegean island of Melos, and new archaeological discoveries continue to be made, as at Kalapodi in Phokis, where a major temple of the classical period seems to have been built on the foundations of a Mycenaean structure. Problems of interpretation remain, however, as can be seen from the recent controversy surrounding newly published Mycenaean tablets from Thebes; the editors claimed these showed evidence for religious festivals, but those claims were later disputed.