His father, Pasqual Maians, fought on the Austrian side in the War of the Spanish Succession and accompanied Archduke Charles VI to Barcelona in 1706; this resulted in the later marginalization of Gregorio Mayans, who lived in Spain when the House of Bourbon dominated it.

He attended the University of Valencia, where he learned from the most distinguished of the novatores, men such as Tomás Vicente Tosca, Juan Bautista Corachán, and Baltasar Íñigo, who introduced him to the ideas of John Locke and René Descartes, which would become important in Mayans' later development.

One of his professors, Borrull, put him in contact with Manuel Martí, dean of Alicante, who became his mentor and guided him in studying the classics, Spanish as well as Latin and Greek.

In 1740, after losing the favour of Arbuixerch, a religious official of the University of Valencia, beset by various controversies, Mayans left and went to Madrid, where he became the royal librarian.

In 1740 he retired to his hometown of Oliva to dedicate himself to his studies and began an active intellectual correspondence with other learned Spaniards and foreigners in Latin and Spanish.

During this period, he continued his discourse with local scholars, including the Valencian physician and philosopher Andrés Piquer, Francisco Pérez Bayer, Muñoz, Cerdá Rico, Cavanilles, and Blasco.

In 1757, he composed a Rhetórica, an exciting anthology of Spanish literature and the best analysis of Castilian prose until Capmany's Teatro de la elocuencia española.