| Honorific-Prefix: | The Honourable |
| Alvaro Antonio | |
| Office: | Governor of Cagayan |
| Term Start: | June 30, 2007 |
| Term End: | June 30, 2016 |
| Predecessor: | Edgar Lara |
| Successor: | Manuel Mamba |
| Office1: | Mayor of Alcala |
| Term Start1: | June 30, 1998 |
| Term End1: | June 30, 2007 |
| Birth Name: | Alvaro Trinidad Antonio |
| Birth Date: | February 19, 1952 |
| Birth Place: | Alcala, Cagayan, Philippines |
| Nationality: | Filipino |
| Party: | UNA (2012-present) |
| Otherparty: | Lakas-CMD (before 2012) |
| Profession: | Lawyer Politician |
| Spouse: | Teresita Ignacio Antonio |
Alvaro Trinidad Antonio, also known by his nickname Bong or Ambong, (born February 19, 1952) is a Filipino politician, who was the Governor of Cagayan from 2007 to 2016. He is a former pro-bono lawyer at the Citizen's Legal Action Office (now known as Public Assistance Office or PAO) and a former mayor of Alcala.
Antonio spent his high school years at San Jacinto Seminary, where he graduated in 1968. He thereafter went to the Pontifical and Royal University of Santo Tomas in Manila, to pursue his college studies. Antonio completed his baccalaureate in philosophy, with honors, in 1972. Antonio proceeded to take up law, also at UST. While finishing his law degree, Antonio joined the Suprema Lex Fraternity.
Antonio started his career as a pro bono lawyer at the Citizen's Legal Action Office (now the Public Attorney's Office). He then ran and won as mayor of his hometown of Alcala, Cagayan. In 2007, he was elected as Governor of Cagayan, with the support of then Congressman Manuel Mamba and Senator Juan Ponce Enrile. Mamba later broke away because of allegations of corruption and jueteng against Antonio. Antonio went on to win two more terms. He took a leave after 3 terms and then lost in 2019 to the incumbent Governor Manuel Mamba landing in third place.