First Secretary of National Defense
1 November 1935 – 15 July 1941

Teofilo L. Sison was born on February 29, 1880 in Dagupan , Pangasinan, to Benito Sison and Escolastica Leuterio.

He studied at the College of San Alberto Magno, obtaining a Bachelor of Arts degree in 1896 and the University of Santo Tomas, B.A., in the same year. He taught in the public schools of Binmaley, Pangasinan from October 1990 until June 1901.

On July 1, 1901 he was appointed interpreter for the Court of First Instance Third Judicial District. It was during his term as court interpreter that he got married to Filomena Solis in Lingayen, Pangasinan on November 19, 1910. He served in such capacity until July 1, 1914, when he was reappointed to a similar position in the 5th District where he remained until September 30, 1914.

After he passed the Philippine Bar examination on September 7, 1914, he established his own law office and engaged in the active practice of his profession.

In June 1916, he was elected Municipal Councilor of Lingayen, a position he held until October 1919. He went on to become Provincial Governor of Pangasinan during the June 1922 election and was re-elected in the general elections of 1925.

Then in June 1928, he was elected for the Senatorial District, comprising the provinces of Pangasinan, La Union and Zambales. As Senator during the period 1928-1931, he was Chairman of the Committees on Civil Service and National Enterprise, and member of the following committees: Finance, Public Works and Communication, Appointments, Justice, Municipal and Provincial Governments, Election and Privileges, City of Manila, Commerce and Industry, Labor and Immigration.

During the 9th Legislative Assembly, he was chairman of the Committee of Justice and member of the following committees: Finance, Public Works and Communication, Appointments, Public Instruction, External Relations, Banks Corporations and Franchise, Commerce and Industry, City of Manila, Municipal and Provincial Governments, Labor and Immigration, Civil Service and Library.

He was appointed Secretary of National Defense in November 1, 1939 during the presidency of Manuel L. Quezon pursuant to the enactment of Commonwealth Act No. 1 or the National Defense Act.