Gary Valenciano was born in Santa Mesa district of City of Manila on August 6, 1964. He is the sixth of seven children of Vicente Calacas Valenciano, a Bicolano from Camalig, Albay and Grimilda Santiago y Olmo (1934–2019) from Arecibo, Puerto Rico. His parents met in New York City, married, and settled in Manila. His mother is a Puerto Rican of Italian descent who sang opera in Manila during the 1960s. Valenciano attended primary and secondary school in La Salle Green Hills.

In 1978, at 12 years old, Valenciano made his first television appearance in an advertisement for Fress Gusto, a now-discontinued soft drink sold by San Miguel Corporation.

He started as a choir singer, then launched his career in singing and show business on May 13, 1983. He first appeared as a solo artist in 1982 in the television programme The Pilita and Jackie Show, and later in Germspesyal and Penthouse Live.

He had his first solo concert in April 1984 at the Araneta Coliseum, followed by a number of albums. Three of his albums were released internationally, including the Christian-inspired album Out of the Dark. He won the Awit Award twelve times in the “Best Male Recording” category alone. He has been called “Mr. Pure Energy” due to his high energy dance performances in concerts.

Valenciano married María Anna Elizabeth “Angeli” Pangilinan, the sister of Senator Francis Pangilinan, on August 6, 1984. Together, they have three children: Paolo Valenciano, a director and the former vocalist of the band Salamin; Gabriel Valenciano, a singer, keyboardist, dancer, and director; and Kiana Valenciano, a model and singer-songwriter.

Valenciano formed the Shining Light Foundation in 1989, focusing on supporting diabetics and a scholarship program that has produced many multi-awarded scholars and students.

As an inspirational artist, he recorded a number of Christian albums and was chosen to do a music video for the Billy Graham Evangelistic Association (BGEA) for a song he co-wrote, “Could You Be Messiah,” in 1994. He was then tapped for Global Mission in Puerto Rico in 1994 where he performed with Michael W. Smith and Steve Green. BGEA tapped him as well as in Amsterdam 2000 where he performed for over 10,500 evangelists. He is a member of the Board of Trustees of Christian Broadcasting Network, producers of The 700 Club. He performed at the 50th anniversary of CBN in Virginia Beach and has guested on The 700 Club USA many times.

In 1998, he became UNICEF Philippines’ first National Ambassador. In 2006, the Doha Asian Games Organising Committee has named Gary Valenciano the official performer of the Asian Games’ theme song, “Side By Side”. In 2008, he marked his tenth year as a UNICEF Ambassador with a visit to Sitio Avocado, a former war zone in Negros Oriental.

Valenciano returned to acting in 2008 by appearing in the drama anthology Maalaala Mo Kaya, where he portrayed a prisoner who finds religion and becomes a born again Christian. That same year, he was nominated for “Best Single Performance by an Actor” in the 22nd PMPC Star Awards for TV.

For his 25th anniversary in 2008, STAR RECORDS, the music arm of ABSCBN, released GV 25, a compilation of songs he composed and recorded sung by music stars of the Philippines like Sharon Cuneta, Rachel Ann Go, Martin Nievera, Piolo Pascual, Jed Madela, Erik Santos, and Christian Bautista.

In 2009, Valenciano released a collaborative album with Martin Nievera called As 1, with the carrier single of the same title.

In 2010, Valenciano was in a Holy Week drama special, Gulong (“Wheel”), a CBN Asia production shown on GMA.

For his 30th anniversary in 2013, his concert ARISE, which was originally staged at the Araneta Coliseum for two nights and restaged at the MOA ARENA to a jam-packed audience, won as PMPC’s Best Concert of the Year. His album With You won the Best Inspirational Album for the same year at the Catholic Mass Media Awards.

He is currently living with type 1 diabetes, and has been an endorser for several wellness products related to the condition. In May 2018, Valenciano started feeling ill after a performance with his son Gabriel for the celebration of his 35th anniversary in showbiz in ABS-CBN’s top-rating Sunday afternoon show, ASAP and had to undergo open heart surgery due to blockage of his left anterior descending artery caused by his diabetes. The procedure was successfully performed on May 6, 2018, and he was released from the hospital by May 12.

On April 17, 2019, Valenciano’s mother died in Orlando, Florida after battling pneumonia, congestive heart failure and H1N1 flu.