poet, essayist, short-story writer, literary scholar and critic, educator, and diplomat, generally considered one of the most distinguished Mexican men of letters of the 20th century.

While still a student, Reyes established himself as an original scholar and an elegant stylist with the publication of Cuestiones estéticas (1911; “Aesthetic Questions”). After receiving his degree in law in 1913, he interrupted his diplomatic career, begun in Paris (1913), by studying and teaching in Madrid at the Centro de Estudios Históricos (1914–19). He served in the Mexican diplomatic service in Spain (1920–27) and as ambassador to Argentina (1927, 1936–37) and to Brazil (1930–36, 1938–39), and he was also frequently a cultural representative of Mexico at various international conferences. During these years he published both scholarly and creative works, distinguishing himself equally in poetry and prose. His poetic essay evoking indigenous chronicles of the discovery and conquest of Mexico, Visión de Anáhuac (1917; “Vision of Anáhuac”), the dialogues and sketches of El plano oblicuo (1920; “The Oblique Plane”), and the essays of Reloj de sol (1926; “Sundial”) reveal the diversity of Reyes's forms and themes. In scholarship and criticism he was equally versatile, specializing in classical Greek literature and Spanish literature of the Golden Age. He also translated English and French works into Spanish and wrote such general works as La experiencia literaria (1942; “The Literary Experience”), a theory of literature.

By the time Reyes returned permanently to Mexico in 1939, on his retirement from the diplomatic service, his position as the master of Mexican letters was virtually unchallenged. He continued to be active in public life and in education while maintaining a vast literary output until his death.