Trelawny was named after Sir William Trelawny, a former Governor of the colony who died in Jamaica in 1772. It has an area of approximately 338^1/4 square miles and has been ranked among the smallest of the parishes in terms of population.

The parish of Trelawny was created in 1774 by a division of the parish of St. James. Its capital was first located at Martha Brae, an inland town, which bore the same name as the Martha Brae River. This site and the access to the sea, proved to be inadequate. The capital was later moved to Falmouth, the port at Palmetto Point. The town of Falmouth was meticulously planned from the start, with wide streets in a regular grid, adequate water supply, and public buildings.

In 1896, the biggest and most magnificent market in the island was constructed in Falmouth. It revives today in a spontaneous and dynamic manner, every Wednesday. One of the outstanding events in the town is the weekly regional market, which draws people and goods from as far away as Kingston.

Falmouth once had a dominant place in the sugar industry. This economic base later shifted to services. The decline of the sugar industry however, resulted in the closure of the port in the early 1970's. Agriculture is the number one economic activity with farming of yam and sugar. The parish has major bauxite deposits which when mined are exported through the Rio Bueno Harbour, bordering the parish of St. Ann. As a coastal town it attracts many tourists and has a strong potential for heritage and eco-tourism as a parish.