Prince Edward County has long been settled by indigenous peoples, and settlement by Europeans followed after the county was created by Upper Canada's founding lieutenant-governor John Graves Simcoe on July 16, 1792.
Prince Edward County was named after Prince Edward Augustus, Duke of Kent (the fourth son of King George III) who was commander-in-chief of British North America.
The county was originally made up of three townships named in honour of three of King George III's daughters.
Before the 20th century, Prince Edward County’s industry was driven by fishing, farming ship-building and shipping. By the 1800s this industry was very prosperous, with hundreds of ships transporting goods to the many ports on Lake Ontario.
In 1998, all of the former municipalities in Prince Edward County amalgamated to form a single-tier municipality as part of province-wide municipal restructuring. Each of the former municipalities is now a ward.