Portland, with its capital town Port Antonio, is located on Jamaica’s northeast coast. It is situated to the north of St Thomas and to the east of St Mary. It is one of the rural areas of Jamaica, containing part of the Blue Mountains, where the Jamaican Maroon communities of Moore Town and Charles Town, Jamaica are located.

The parish has a variety of complex landforms; the entire coastline is dotted with caves, bays, rivers, waterfalls and hills. There are fourteen caves, which include those at Buff Bay, Orange Bay, Hope Bay, Port Antonio, Boston Bay, Long Bay, Innis Bay and Nonsuch. There are also 17 rivers, which form a network throughout the parish. The largest are the Rio Grande, Buff Bay and Hectors rivers.