Marinha Grande is a municipality in the district of Leiria, Portugal. It has a population of 38,030 and a total area of 187.1 km².

The town is composed of three parishes: Vieira de Leiria, Marinha Grande, and Moita. It is located right in the middle of the Leiria pine forest, a national forest, and near exquisite beaches such as Praia da Vieira, Nazaré, and São Pedro de Moel.Marinha Grande is Portugal's biggest glass manufacturer, and it is also the European capital for the moulding industry, with 250 companies operating there.

The beach of São Pedro de Moel to the west is one of the most popular holiday resorts in the region.