Santiago Posteguillo Gómez is a Spanish philologist, linguist, and author, born in Valencia in 1967. He is a well-known figure for his novels set in Ancient Rome, notably his Scipio Africanus and Trajan trilogies.

Posteguillo is a senior lecturer in English Language and Linguistics at the Universitat Jaume I in Castellón, Spain. In addition, he is the president of the European Association of Languages for Specific Purposes and serves on the Editorial Board of the international journals English for Specific Purposes and Written Communication.

His notable awards include the Best Historical Novelist award, Hislibris 2009, and the Valencian Literature Award in 2010. On October 16, 2018, he was honored with the prestigious Premio Planeta for his novel Yo, Julia.