Her interest in music was evoked in her childhood by American musicals from the 1950s, Mexican Mariachi bands and Italian music from the 1960s. In her early teens, Power discovered The Beatles and Bob Dylan, which inspired her to compose music. After receiving a guitar as a birthday gift, she learned chords and wrote her first songs.

Born in Los Angeles, Romina Power is the eldest daughter of American screen idol Tyrone Power and his second wife, Mexican Actress Linda Christian. After her parents divorced in 1956, she and her younger sister Taryn lived with their mother in various places, mainly in Mexico and Italy where she and her sister spent much of their childhood, although Romina attended college in England.

She met her singer and actor husband Albano Carrisi whilst acting in films in the 1960s. They married in 1970. In 1975 they formed a singing duo, which became well known in Italy, Germany, Austria, Spain, France, Greece, Latin America, Eastern Europe and the USSR, releasing multiple albums in different languages and achieving 7th place in both the 1976 and 1985 Eurovision Song Contest for Italy. Their biggest hits included "Felicità", "Sharazan", "Tu soltanto tu", "Ci sarà", "Sempre sempre", and "Libertà". The couple divorced in 1999. They have four children:

She appeared in several mainly Italian-language films from the age of 14, including the 1968 adaptation of the Marquis de Sade's novel Justine, directed by Jesus Franco.

In 2005 Power was a judge in the Italian TV show Ballando con le Stelle (Dancing with the Stars). Between 2006 and 2007 she organized exhibitions of her paintings, mainly in Milan. At the same time she dedicated herself to directing her film Upaya (2006).

In spring 2007 Power bought a house in Sedona, Arizona and decided to leave Italy forever and move to the United States. The clamorous interview in which she revealed her plans was published in an Italian magazine Diva e donna. According to Romina, she was perceived by the Italian public merely as a performer of Il ballo del qua-qua (a song for children, from her and Al Bano's album Felicità, 1982), and for her it was difficult to establish herself in Italy as a Painter and Writer. Furthermore, she was disturbed by the intrusive attention of the local press, that published multiple articles with speculations about her private life and the disappearance of her daughter Ylenia.

Shortly after her relocation, in 2008, her mother Linda Christian was diagnosed with colon cancer, so she went to live in her mother's house in Palm Springs where she remained for three years, until her mother's death on 22 July 2011. In a November 2009 interview she gave to Italian TV she stated she had considered, at least for some time, a possible return to Italy. At present Romina Power is permanently living and working in the United States where she resides full-time.

In the fall of 2012 her album Da lontano was released, containing songs written in 1999. In the summer of 2013 Al Bano and Romina Power reunited, reportedly only on a professional basis and for one final time, for a concert performance in Moscow. In 2015 Al Bano and Romina Power reunited again for a guest appearance in the Sanremo Festival.