The parish of Saint Mary was formed in 1675, it is situated to the northeastern section of the island and is located at latitude 18°09'N, longitude 77°03'W. It is bordered by Portland in the east, St. Ann in the west, and parts of St. Catherine and St. Andrew in the south. It's chief town is Port Maria.
The parish covers an area of 610 km², making it Jamaica's fifth smallest parish. The terrain is mountainous, rising up to almost 4,000 feet at the highest point, but there are no distinctive mountain ranges. The climate is varied, like most parishes on the island. The eastern section of the parish has shale rock and an intricate surface draining pattern, while the western section is limestone with predominantly underground rivers.
There are three main rivers in Saint Mary, the Rio Nuevo, Wag Water River and White River. The parish also has two hospital (Annotto Bay and Port Maria) and over 30 health centers.
The parish has a good variety of agricultural resources. The principal products are bananas, sugar cane, citrus, pimento, cocoa, coconuts and coffee. In recent years, however, agriculture has been on the decline, which may be due to the problems that the Jamaican banana export has been facing as well as natural disasters.
St. Mary's parish, had once been listed as one of the poorest in Jamaica, but over the past 10 years there have been substantial improvements in the economy due to the influx of investments
in infrastructure, including a new international airport (Ian Fleming International Airport), a new highway, and development of luxury resorts such as Goldeneye and Golden Clouds. The new intercoastal highway constructed in 2005 has benefitted the parish and has brought significant increase to tourism-related activities.
St. Mary is well known for its history which dates back to the days slavery. Today, numerous National monument still stands in the Parish, amomg them are;
- Rio Nuevo Taino Site - The largest Taino site in this area. It covers an area of some 21,000 square meters.
- Annotto Bay Baptist - Built in 1824 - it was the first Baptist Church to be constructed in St. Mary.
- Holy Trinity Anglican - beautiful historic Georgian building erected on land donated by Henry Rigg in 1828.
- Fort Haldane - situated at Port Maria in the parish of St. Mary and was erected in 1759.
- Fort Oracabessa - built during the War of Trade. Erected by John Allen in 1752
- Brimmer Hall Great House - built during the 18th Century by the plantocracy during the days of slavery.
- Prospect Great House - On the Prospect Estate is an early Eighteen Century Great House.
- Quebec Great House - boasts basic Georgian features, such as symmetry and a central portico.
- Galina Lighthouse - over 40 feet high. The light is approximately 60 feet above sea level.
- Firefly House - originally called "Look Out" by famous pirate Henry Morgan as it was used for that purpose.
- Harmony Hall House - Indicative of Jamaican-Georgian architectural style with its characteristic features of plantation houses in the nineteenth century.
- Castleton Botanical Garden - established on the 19th Nov 1862
- Claude Stuart Park - In 1977 the Victoria Park in Port Maria, St. Mary was renamed the Claude Stuart Park.
- Rio Nuevo Battle Site - the site of the final pitched battle between British and Spanish forces to determine possession of Jamaica.
- Port Maria Court House - Originally built in 1821,this Georgian architecture housed the court house and police station until1988
The Parish is divided into three consituencies Central, South-Eastern and Western St. Mary and thirteen Council divisions namely Highgate, Port Maria, Annotto Bay, Gayle, Richmond, Casleton, Carron Hall, Boscobel, Oracabessa Belfield, Hampstead, Port Maria and Retreat.