Francisco Castro Ada (September 26, 1934 – March 2, 2010) was a Northern Mariana Islander politician who served as the first lieutenant governor of the Northern Mariana Islands from January 9, 1978 to January 11, 1982, under Carlos S. Camacho, the territory's first governor. Ada is credited with spearheading the construction of much of the modern infrastructure in the Northern Mariana Islands, including Francisco C. Ada/Saipan International Airport, the Commonwealth Ports Authority, and the Northern Marianas College.