Gustavo Alfredo Santaolalla (Spanish: [ɡusˈtaβo alˈfɾeðo santaoˈlaʝa]; born 19 August 1951) is an Argentine composer, record producer and musician. He is the recipient of numerous accolades for his works, including two Academy Awards for Best Original Score, a Golden Globe, two Grammy Awards and 17 Latin Grammy Awards. He is known for his minimalist approach to composing and for his influence in the Latin rock music genre.

Involved in music from a young age, he began a professional career in 1967 founding the band Arco Iris, who were influential to the rock nacional genre. Fleeing the rule of the Argentine military junta and the dictatorship of the National Reorganization Process, Santaolalla moved to Los Angeles in 1978. After returning to Argentina in the 1980s and taking a musical sabbatical, he became a leading figure in the rock en español movement, producing records for over 100 artists. He established the neotango group Bajofondo in 2001. Music from his 1998 solo album Ronroco caught the attention of filmmakers and led to a career expansion into film scores, beginning with Amores perros (2000), 21 Grams (2003) and The Motorcycle Diaries (2004).

Santaolalla rose to fame for creating the scores for Brokeback Mountain (2005) and Babel (2006), for which he received two Academy Awards for Best Original Score in consecutive years. He scored I Come with the Rain (2009) and Biutiful (2010). Santaolalla further gained recognition for his work on The Last of Us game series, composing the 2013 game and its 2020 sequel. In 2014, he composed his first animated film, The Book of Life, and his first Argentine film, Wild Tales. He scored the short film Borrowed Time (2015) and co-composed the documentary Before the Flood (2016). Santaolalla returned to reprise his themes and co-compose the score for the 2023 television adaptation of The Last of Us and composed an original score for October 2024 showings of the 1931 Spanish-language Dracula film by the Los Angeles Opera.

Not learned in reading or writing musical notation, Santaolalla prefers composing his scores mostly by himself. Favouring instruments like the ronroco, he adopts a minimalistic approach when composing and prefers to capture humanistic elements of performances. He compares his philosophy of favouring minimalism in music to parkour, comparing the calculations of athletes before landing to his measured selection of musical notes before playing them. By contrast, his live performances have been noted for their vibrancy. For his influence in Latin music, Santaolalla was recognized as a BMI Icon during the 15th annual Latin Awards Ceremony in 2008 and received the Latin Grammy Trustees Award in 2023. In his personal life, he has two children with his wife, and is engaged with winemaking.

Gustavo Alfredo Santaolalla was born in El Palomar, Argentina on 19 August 1951. Santaolalla was born to a stay-at-home mother and a father working in the advertising industry for J. Walter Thompson. His family has roots in Spain; his grandfather was Andalusian and his grandmother was Basque. When Santaolalla was five, he was given his first guitar by his grandmother for his birthday; he "immediately connected in a sort of a spiritual level with the music", and began musical tutelage with a hired teacher. When he was ten, his teacher declined to continue attempting to educate him; according to Santaolalla, the teacher told his mother "his ear is stronger than my music". He had also lived in the community of Ciudad Jardín Lomas del Palomar.

In his pre-teenage years, Santaolalla wrote songs in English which "mimick[ed]" the music of bands like the Beatles; at twelve, he was gifted his first electric guitar. In his teenage years, Santaolalla had aspired to become a musician such that he designed a logo for a record label he had dreamed of owning. Santaolalla had been an altar boy at a Catholic church, aspiring to join the seminary, but had a falling out with his dedication to religion after pondering why God would let evil and Hell exist despite His goodness. The priest had called Santaolalla's father regarding performing an exorcism on the boy for his "heresy", but Santaolalla's father supported his exit from the church. By 1966, Santaolalla, then 15, had been arrested by the military juntas governing Argentina, according to him because he had long hair and played an electric guitar, despite not partaking in drugs or being involved in political activities. The first time Santaolalla was arrested, his father arrived to collect him, questioning the authorities about what crime Santaolalla had committed. The arrests continued throughout his adolescence.

Santaolalla's music career began in 1967 when he co-founded the group Arco Iris, a rock band that helped create rock nacional. He played guitar and sang in the band, which included wind instrument player Ara Tokatlian [es], bass player Guillermo Bordarampé [es], percussionist Horacio Gianello [es] and their vocalist Danais Winnycka [es], who became their spiritual guide. The group lived a communal lifestyle, practicing celibacy, vegetarianism, forgoeing alcohol and drugs, and were engaged with Eastern religion. The band rose to prominence with the song "Mañana campestre" from their third album Tiempo de Resurrección  [es].

After seven Arco Iris albums, Santaolalla left following a disagreement with Tokatlian, and amid concerns that arose with Santaolalla halfway through their existence that "any group that is so inner directed runs the risk of turning into a cult". Santaolalla called his mother, who orchestrated an operation to "rescue" him from the community he had found to be "oppressive". Santaolalla thereafter founded the hard rock group Soluna. With the 1976 Argentine coup d'état, Santaolalla experienced hard times under the National Reorganization Process and moved to Los Angeles, California in 1978, living undocumented for several years. He formed the group Wet Picnic, but had no commercial success with them. At this point, Santaolalla described his life as "[Eight years of eating shit every morning]", and lived a "[fantasy]" of a drug-abusing rock star. Afterwards he lived in a hotel in New York, experiencing poverty with his creative partner Aníbal Kerpel.