Tulio Larrinaga (born January 15, 1847) was a Puerto Rican politician who served as a Resident Commissioner in the United States House of Representatives. Representing Puerto Rico at-large, he held office as a Unionist Party representative from December 4, 1905, to March 3, 1911. During this period, he was a historical member of Congress at a time when Puerto Rico’s political relationship with the United States was still being defined in the early twentieth century.

Larrinaga served three terms in Congress, reflecting sustained support for his role as Puerto Rico’s at-large representative. As a Unionist, his tenure coincided with the broader Unionist movement on the island, which sought to shape Puerto Rico’s political status and advocate for its interests within the U.S. political system. Although specific committee assignments, legislative initiatives, and contact details are not recorded in the available metadata, his service from 1905 to 1911 marks him as a significant early congressional figure in Puerto Rico’s representation before the federal government.