| Term Start: | September 7, 1878 |
| Term End: | September 29, 1878 |
| Birth Date: | August 15, 1811 |
| Birth Place: | Santo Domingo, Captaincy General of Santo Domingo |
| Death Date: | December 13, 1896 (aged 85) |
| Death Place: | Santo Domingo, Dominican Republic |
| Nationality: | Dominican |
| Spouse: | Maria de la Concepción y Lara Suazo |
| Children: | 4 |
| Office: | President of the Dominican Republic |
| Predecessor: | Ignacio María González |
| Successor: | Cesareo Guillermo |
Jacinto del Rosario de Castro (August 15, 1811 – November 13, 1896) was a politician from the Dominican Republic.
Castro was born and died in Santo Domingo. He served as the 1st acting president of the Dominican Republic from September 7, 1878 until September 29 of that year.
Jacinto de Castro was born on August 15, 1811 in Santo Domingo, he was the natural son of Dolores Ana de Castro Urrutia, who in turn was the daughter of Juan María de Castro Guzmán and Mercedes de Urrutia Fox. The name of the father is unknown. He was baptized on August 27 of that same year in the Cathedral of Santo Domingo with the name of Jacinto del Rosario de Castro.
A lawyer by profession, he lived in Baní, where he took an active part in the actions of the Dominican War of Independence.
His quality as a respectable and enlightened person earned him positions of importance in the nation, including: deputy, plenipotentiary, prosecutor of the Supreme Court of Justice and minister of Justice and Public Instruction.
He was a founding member in 1846 of the patriotic society Friends of the Country, however, in 1861 he supported the annexation to Spain.
He served as president of the Supreme Court of Justice when on September 2, 1878, the President of the Republic, Ignacio María González resigned his position, a situation that caused him to constitutionally provisionally occupy the first magistracy of the nation, to, within the deadlines established by the Constitution, call for the election of the definitive replacement for President González.
Upon assuming the Presidency, Jacinto de Castro organized a Provisional Government until elections were held to choose the new Head of State.
As Secretary of Justice and Public Instruction, he appointed Angulo Guridi; Pedro M. Aristy, of Finance and Commerce, and Pedro Guillermo, Minister of War and Navy and in charge of the Ministry of Foreign Affairs.
As delegate of the Cibao Cabinet, he appointed General Ulises Heureaux.
On September 29 of the same year, Jacinto de Castro resigned from the presidency of the Republic. He took the reins of the country through a Council of Secretaries of State, until February 27, 1879, when Cesáreo Guillermo was elected.
Jacinto de Castro married María de la Concepción de Lara Suazo, daughter of Juan Bautista de Lara Pérez and María Salomé Suazo Arias, in Baní on June 3, 1835. They had four children:
According to the oral tradition of the Mañón family, Juana Francisca Mañón had eight children with Jacinto de Castro. They are these: Jacinto Mañón (b. 1868), Juan Francisco Mañón (b. 1869), Darío Mañón, Mario Mañón, Ercilia Mañón, Jorge Rogelio Mañón (b. 1877), Ana Graciela Mañón (b. 1879) and Luis Enrique Gregorio Mañón (b. 1881).
Likewise, the oral tradition of the García family also attributes two sons of Monserrat García to Jacinto de Castro. These are Mercedes García, born around 1853, and Ramón María García.
Jacinto de Castro died in Santo Domingo, on December 13, 1896 at the old age 85.