St. Petersburg is a city in Pinellas County, Florida, United States. As of the 2020 census estimate, the population was 271,842, making it the fifth-most populous city in Florida, the second-largest city in the Tampa Bay Area, after Tampa, and the largest in the state that is not a county seat (the city of Clearwater is the seat of Pinellas County). Along with Clearwater, these cities are part of the Tampa-St. Petersburg-Clearwater Metropolitan Statistical Area, the second-largest in Florida with a population of around 2.8 million. St. Petersburg is on the Pinellas peninsula between Tampa Bay and the Gulf of Mexico, and is connected to mainland Florida to the north.
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