Largo is the third largest city in Pinellas County, Florida, United States, and the fourth largest in the Tampa Bay area. As of the 2020 census, the city had a population of 82,485, up from 77,648 in 2010. Largo was first incorporated in 1905. In 1913, it became the first municipality in Pinellas County to adopt a council-manager government. It switched back and forth between "town" and "city" a few times, and became a city again in 1974. It was an exporter of agricultural products until the 1960s population growth began to transform it into a bedroom community. From 1905 to 2010, Largo grew in area from 9⁄16 of a square mile (1.5 km2) to about 19 square miles (48 km2), and in population from about 300 people to more than 70,000. Largo began as a rural farming community and became the third largest city in Florida's most densely populated county. Largo is a sister city to Tosayamada, Kōchi, Japan, and has been named a National Arbor Day Tree City for 35 years in a row as of 2023.