Diego Silang (December 16, 1730 - May 28, 1763) was a revolutionary leader who conspired with British forces to overthrow the Spanish in the northern Philippines and establish an independent Ilocano nation. His revolt was fueled by grievances stemming from Spanish tributes and abuses, and his belief in self-government, that the administration and leadership of the Roman Catholic Church and government in the Ilocos Region should belong to trained Ilocano officials.

Born in Aringay, Pangasinan (an area in present-day Caba or Aringay, La Union), he worked as a messenger for a local Castilian priest in Vigan, Ilocos Sur. Bright, passionate and conversant in Spanish, he ferried correspondence from the Ilocos to Manila, journeys that gave him his first glimpse of colonial injustice and that planted the seeds of rebellion.

Spain allied with France during the Seven Years War against Great Britain. In so doing, the British sought to diminish the Spanish empire. British naval forces took over Manila in the early 1760s that inspired uprisings in the farthest north of Ilocos Norte and Cagayan, where anti-Spanish sentiments festered. While Silang initially wanted to replace Spanish functionaries in the Ilocos with native officials, and volunteered to head Ilocano forces against the British, desperate Spanish administrators transferred their powers to the Catholic Bishop of Nueva Segovia (Vigan) who in turn rejected Silang's call. Silang's group attacked the city and imprisoned its priests. He then began an association with the British who appointed him governor of the Ilocos in their behalf and promised him military reinforcement. The British force never materialized.

He was killed by one of his friends, a Spanish-Ilocano mestizo named Miguel Vicos who was paid by church authorities to assassinate him.

His wife Gabriela Silang continued his fight but lost.