Martin Persson Nilsson (Stoby, Kristianstad County, 12 July 1874 – Lund, 7 April 1967) was a Swedish philologist, mythographer, and a scholar of the Greek, Hellenistic and Roman religious systems. In his studies he combined the literary evidence with the archaeological evidence, linking historic and prehistoric evidence for the evolution of the Greek mythological cycles.
Beginning in 1900 as a tutor at the University of Lund, he was appointed Secretary to the Swedish Archaeological Commission working in Rhodes, in 1905. In 1909 he was appointed Professor of Ancient Greek, Classical Archaeology and Ancient History at Lund. Later, Nilsson was Secretary of the Royal Society of Letters in Lund and an Associate of the Royal Swedish Academy of Letters, History and Antiquities, in Stockholm. In 1924 he was made a corresponding member of the Prussian Academy of Sciences.
Nilsson's best-known work in German is Geschichte der Griechischen Religion in the Handbuch der Altertumswissenschaft, which went through several editions. Nilsson had previously published it under the title Den Grekiska Religionens Historia (1922). In English his Minoan-Mycenaean Religion, and Its Survival in Greek Religion is more often quoted. Other important works include: