The emperor of Ethiopia, also known as the Atse, was the hereditary ruler of the Ethiopian Empire, from at least the 13th century until the abolition of the monarchy in 1975. The emperor was the head of state and head of government, with ultimate executive, judicial and legislative power in that country. A National Geographic article from 1965 called imperial Ethiopia "nominally a constitutional monarchy; in fact [it was] a benevolent autocracy".

The Ethiopian Empire, also formerly known by the exonym Abyssinia, or simply known as Ethiopia, was a sovereign state that historically encompasses the geographical area of present-day Ethiopia and Eritrea from the establishment of the Solomonic dynasty by Yekuno Amlak approximately in 1270 until the 1974 coup d'etat by the Derg, which dethroned Emperor Haile Selassie. By 1896, the empire incorporated other regions such as Hararghe, Gurage and Wolayita, and saw its largest expansion with the federation of Eritrea in 1952. Throughout much of its existence, it was surrounded by hostile forces in the African Horn; however, it managed to develop and preserve a kingdom based on its ancient form of Christianity.