Dughet was born in Rome in 1615, the son of a French cook. He became one of the most famous landscape artists of the 17th century, together with Claude Lorrain and Salvator Rosa. In 1630 his sister Anne Marie married the painter Nicolas Poussin and Gaspard became his loyal pupil, eventually earning the nickname Gaspard Poussin. He adopted a classical style of painting, influenced by the idealized interpretation of nature introduced at the beginning of the century by the Bolognese artists Annibale Carracci and Domenichino. Dughet’s “pure” landscapes reflect his enjoyment of ruins and ancient fables, often set in the Alban Hills, Tivoli or the Sabina area. He spent most of his life in and around Rome, travelling to Milan and Perugia in 1635 and sojourning in Florence and Naples from 1641 to 1646.
Dughet’s easel painting was skilful and prolific and he was also well-known as a fine painter of frescoes, such as the large cycle depicting landscapes with episodes from the life of Elijah in the Church of San Martino ai Monti in Rome. He became famous in the city for his talent as a decorator and received commissions from some of the most important families, including Pamphilj, Colonna and Borghese.