Largo is the third largest city in Pinellas County, Florida, United States, as well as 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.