Lemuria (/lɪˈmjʊəriə/), or Limuria, was a continent proposed in 1864 by zoologist Philip Sclater, theorized to have sunk beneath the Indian Ocean, later appropriated by occultists in supposed accounts of human origins. The theory was discredited with the discovery of plate tectonics and continental drift in the 20th century.

The hypothesis was proposed as an explanation for the presence of lemur fossils on Madagascar and the Indian subcontinent but not in continental Africa or the Middle East. Biologist Ernst Haeckel's suggestion in 1870 that Lemuria could be the ancestral home of humans caused the hypothesis to move beyond the scope of geology and zoogeography, ensuring its popularity outside of the framework of the scientific community.

Occultist and founder of theosophy Helena Blavatsky, during the latter part of the 19th century, placed Lemuria in the system of her mystical-religious doctrine, claiming that this continent was the homeland of the human ancestors, whom she called Lemurians. The writings of Blavatsky had a significant impact on Western esotericism, popularizing the myth of Lemuria and its mystical inhabitants.

Theories about Lemuria became untenable when, in the 1960s, the scientific community accepted Alfred Wegener's theory of continental drift, presented in 1912, but the idea lived on in the popular imagination, especially in relation to the Theosophist tradition.

Lemuria was hypothesized as a land bridge, now sunken, which would account for certain discontinuities in biogeography. This idea has been rendered obsolete by modern theories of plate tectonics. Sunken continents such as Zealandia in the Pacific, and Mauritia and the Kerguelen Plateau in the Indian Ocean do exist, but no geological formation under the Indian or Pacific oceans is known that could have served as a land bridge between these continents.^{[citation needed]}

In 1864, "The Mammals of Madagascar" by zoologist and biogeographer Philip Sclater appeared in The Quarterly Journal of Science. Using a classification he referred to as lemurs, but which included related primate groups, and puzzled by the presence of their fossils in Madagascar and India, but not in Africa or the Middle East, Sclater proposed that Madagascar and India had once been part of a larger continent (he was correct in this; though in reality this was Mauritia and the supercontinent Gondwana).

The anomalies of the mammal fauna of Madagascar can best be explained by supposing that... a large continent occupied parts of the Atlantic and Indian Oceans... that this continent was broken up into islands, of which some have become amalgamated with... Africa, some... with what is now Asia; and that in Madagascar and the Mascarene Islands we have existing relics of this great continent, for which... I should propose the name Lemuria!

Sclater's theory was hardly unusual for his time; "land bridges", real and imagined, fascinated several of Sclater's contemporaries. Étienne Geoffroy Saint-Hilaire, also looking at the relationship between animals in India and Madagascar, had suggested a southern continent about two decades before Sclater, but did not give it a name. The acceptance of Darwinism led scientists to seek to trace the diffusion of species from their points of evolutionary origin. Before the acceptance of continental drift, biologists frequently postulated the existence of submerged land masses to account for populations of land-based species now separated by barriers of water. Similarly, geologists tried to account for striking resemblances of rock formations on different continents. The first systematic attempt was made by Melchior Neumayr in his book Erdgeschichte in 1887. Many hypothetical submerged land bridges and continents were proposed during the 19th century to account for the present distribution of species.