Leo Bagrow (born Lev Semenovich Bagrov; 6 July 1881 – 10 August 1957) was a Russian-born historian of cartography, founder of the journal Imago Mundi. He grew up in Russia, and initially pursued a career within the Imperial Russian Navy. In naval service, he traveled extensively to conduct surveying work. During this time, he encountered the historical map collection of Arctic explorer Adolf Erik Nordenskiöld in Helsinki and became interested in the history of mapmaking.
Following the outbreak of World War I, he taught navigation and what may have been the world's first academic course on the history of geodesy and cartography in Saint Petersburg. By this time he had also begun publishing scholarly articles and receiving international recognition within his field. Following the Russian Revolution, he fled the country, never to return. He settled in Berlin, where he began working as a dealer in antique maps. There he met Hans Wertheim, with whom he founded the world's first international scholarly journal dedicated to the history of cartography, Imago Mundi. The first issue was published in 1935; Wertheim, who was Jewish, was soon forced to flee Nazi Germany to Belgium, where he died.
Bagrow managed to find a new publisher for the journal in London, but stayed in Germany until April 1945, when he was evacuated with the help of Swedish colleagues with the last diplomatic flight from Berlin to Stockholm. He would spend the rest of his life in Sweden, where he was granted citizenship in 1952 and where he enjoyed the patronage of King Gustav VI Adolf.