| Honorific-Prefix: | The Honourable |
| Proceso Sebastián | |
| Office1: | Senator of the Philippines |
| Term Start1: | December 30, 1941 |
| Term End1: | December 30, 1947 |
| Office2: | Governor of Cagayan |
| Term Start2: | 1926 |
| Term End2: | 1929 |
| Predecessor2: | Fermin Macanayan |
| Successor2: | Vicente Formoso |
| Office3: | Member of the Philippine House of Representatives from Cagayan's 2nd district |
| Term Start3: | 6 June 1922 |
| Term End3: | 6 June 1925 |
| Predecessor3: | Bonifacio Cortes |
| Successor3: | Antonio Guzman |
| Birth Date: | 26 January 1892 |
| Birth Place: | Claveria, Cagayan, Captaincy General of the Philippines |
| Nationality: | Filipino |
| Party: | Nacionalista (from 1925) Democrata (1922–1925) |
| Alma Mater: | University of the Philippines |
| Occupation: | Politician |
| Profession: | Lawyer |
Proceso Esmeria Sebastián (January 26, 1892[1] - ?) was a Filipino lawyer, politician and diplomat.
Sebastián was born in Claveria, Cagayan, on January 26, 1892, to Gregorio Sebastián and Filomena Esmeria. He obtained his law degree from the University of the Philippines. After passing the Philippine Bar Examination in 1915, he worked as a lawyer in his home province.[1]
Sebastián was elected to the House of Representatives of the Philippines in 1922 representing the 2nd District of Cagayan for the Democrata Party. He served until 1925[2] and afterwards was elected governor of Cagayan, serving from 1926 to 1929.[3] As a member of the Philippine Legislature, he joined the Second Independence Mission to the United States.[1]
In 1931, he was appointed as a judge,[4] and spent the rest of the decade serving in the Visayas, Laguna and eventually in Manila.[1]
In 1941, Sebastián was elected to the Philippine Senate as a candidate of the Nacionalista Party. Because the Japanese invaded the Philippines shortly afterwards, he was only able to take office in 1945, following the liberation of the Philippines by the Americans.[5] During the Japanese occupation, he was appointed as an associate justice of the Court of Appeals by President Jose P. Laurel.[1]
As senator, Sebastián headed the Philippine delegation to the first UNESCO conference in Paris in 1946, where he was elected as one of the vice presidents of the UNESCO Assembly.[1]
After his term in the Senate, Sebastián was appointed by President Manuel Roxas to become Envoy-Extraordinary and Minister-Plenipotentiary to China in 1948. He was later appointed by President Elpidio Quirino as ambassador to Italy and the Holy See, France, Belgium, the Netherlands, the United Nations Office at Geneva and ultimately Indonesia before retiring from the diplomatic service in 1954.[1]
Sebastián was elected to the Quezon City Council in 1959.[1]
He was married to Antonia Villanueva and had three children.[1]