In the mid 1800s people began settling in the area that is recognized today as Largo. The first settlers included recognizable names such as Belcher, McMullen,McKay, Taylor and Wilcox who had a significant role in shaping the history of Largo. By 1886 the Orange Belt Railroad, later known as the Atlantic Coast Line, was constructing a railroad through the area and a group of residents living here at the time wanted a train station in the still unnamed area. The station had to have a name and after much discussion it was agreed the town should take the name of a nearby lake, Lake Largo. The lake was later drained, but was located in the area where the Largo Central Park Nature Preserve is currently located. The first post office was built in 1888. By the end of the 1800s Largo was becoming the .Citrus City. because of its rich farmland and accessibility by rail.

In 1905, the Town of Largo was incorporated and measured one square mile. Pinellas County was incorporated in 1912. The Town of Largo in 1913 became only the second community in the nation to adopt the Commission-Manager form of government. The town population by then exceeded 300 people. That same year, the first electric street lights were installed. The Largo Library opened in 1916 using a single room in Town Hall. Largo officially became a City in 1925 as the town limits were extending all the way to where Belleair Beach is today. A 24 member Chamber of Commerce was established in 1925. More than 1,000 people were living in the City by that time. A severe freeze crippled the citrus industry in the late 1920s and then, during the depression era, the City was forced by a State Supreme Court ruling to revert back to a being a town while contracting its boundaries to the original 1905 town boundaries.

Throughout the early to mid 1940s, the effects of World War II impacted the way people lived and conducted business in the Town of Largo in much the same way the rest of the country was affected. By the end of the decade the war was over and things were getting back to normal. In 1948, the first movie theater opened on West Bay Drive featuring Abbott and Costello.s .Buck Private Come Home.. By 1950, the Town.s population exceeded 1,500 people and would more than triple to 5,000 by 1955 as a result of the City.s new annexation policies.

Another freeze in 1962 severely hurt the citrus industry and the owners of the groves began to sell the large tracts of land to developers for future home sites. As the population grew and subdivisions were built, the City constructed a new town hall, library, and recreation center to meet the needs of the growing community.

By the mid 1970s, the Town of Largo once again was a city after more than 70 years. The City measured approximately 13 square miles with a population of almost 60,000 residents. During this same time the City began acquiring the County Fairgrounds property and surrounding land for the future development of Largo Central Park. Throughout the latter parts of the 20th century the City saw continued growth in the population due to annexation policies and development. As the City celebrates its Centennial it has grown to over 74,000 residents and continues to seek opportunities for growth.