Born in Bani, Pangasinan he completed his studies at the University of the Philippines with a degree of Bachelor of Arts in Economics in 1971. He received his degree in law in 1975. One of the 1988 TOYM Awardees for Public Service.
He became a legal assistant to the Paredes, Poblador, Nazareno, Azada and Tomacruz Law Firm from 1975 to 1976 and elevated to Associate Attorney in 1976. He became a Partner in 1980 and the firm was called the Poblador, Azada, Tomacruz, Paredes, Cacanindin and Orbos Law Firm. He resigned to the post in 1983 to help in the propaganda campaign to oust Ferdinand Marcos.
In 1987, Orbos ran and won as congressman and represented the first district of Pangasinan from November 1987 to December 1989. He was cited as one of the most active congressman in the 8th Philippine Congress. He was cited as one of the 1989 Ten Outstanding Young Men (TOYM) for Public Service and legislation.
On January 4, 1990, President Corazon Aquino appointed him as secretary of the Department of Transportation and Communications. As secretary, one of the most notable contributions was the yellow lane, where the two outermost lanes of 4-6 lane roads were allotted for public utility vehicles, mostly buses.
On December 21, 1990, Orbos was appointed by Aquino as her executive secretary. During that time, Iraq already occupied Kuwait and it had plans to make further attacks on Saudi Arabia. Orbos facilitated measures for the repatriation and communication to overseas Filipino workers working in the Middle East.
He resigned on July 1991 and returned to private life. He co-hosted GMA Network's Firing Line, a TV panel talk show with Teodoro Benigno, Mrs. Aquino's former press secretary. During the 1992 elections, he actively supported fellow Pangasinense Fidel Ramos to the presidency.
In 1995, he resigned as host of the TV program and ran for the position of governor of the province of Pangasinan. He won the election via landslide. As governor, he initiated the establishment of a Provincial Action Center to provide public direct access to all provincial and national government offices to respond to needs of his constituency. Orbos gained the highest public approval rating as governor.
Even if he was predicted to win a reelection as governor, he ran in the 1998 elections for the position of Vice President as a running mate of Renato de Villa. However, he was lost to Senator Gloria Macapagal-Arroyo.
In late 1998, Orbos was offered by Menardo Jimenez, president of GMA Network to host an open debate program for TV. Jimenez is a native of Dasol, located in the first district of Pangasinan. As a good friend, he gladly accepted the offer and was paired with U.P. professor Solita (Winnie) Monsod. Debate with Mare and Pare became a phenomenal interactive and open talk show in the Philippines. The talk show was the only latetime TV program earning a high audience rating.
Despite offers to enter again to public office, he refuse so because he already called his current job "political". He earned the respect of the public for being neutral on most issues.
Oca or Pareng Oca, to whom he is often called, is married to Rosita Sioson.