The D. Diniz Literary Award, established by the Casa de Mateus Foundation in 1980, is intended to reward works published in the year preceding the award in the categories of poetry, fiction, essay or theatre, including foreign books with a strong connection to Portuguese culture or translators of a relevant literary work due to the quality of the translation.

Since 2016, the jury has been composed of Nuno Júdice, who presides, along with Fernando Pinto do Amaral and Pedro Mexia. The prize is awarded in accordance with the provisions of the D. Diniz Literary Award Regulations.