Mayo, Florida: Current Lafayette County Courthouse. – Ebyabe, CC BY-SA 2.5 – Wikimedia Commons Mayo is located in Lafayette County. About 1,055 people live here (as of 2020). Between 2010 and 2020, the population declined from 1,237 to 1,055. The region is at 27 meters above sea level. The area covers about 2.3 square kilometers. There are about 89 streets in Mayo. The postal codes are 32066. The dialing code is 386. Mayo is town in and county seat of Lafayette County, Florida, United States. Among other things, Mayo has restaurants, supermarkets and banks.