She was born Giovanna Scoglio in Liverpool, England, to an aristocratic Sicilian father, Pietro Scoglio, and an Irish mother, Eileen Sullivan. She lived in Rome, Italy, and moved to the United States at age fourteen where she studied and worked in New York City. Gia graduated from Bayside High School (New York City) in Queens, New York. For a time she was undecided on what to do next. She worked in New York as a filing clerk for an insurance company and for a number of airlines.
She studied acting at night and made appearances on some radio shows and television quiz shows. At the end of 1954 an agent had her tested for the role of Mary Magdalene in a movie which was to be made called The Gallileans. She did not get the part but was signed to contracts by both Universal Studios and Columbia Pictures in Hollywood. Using the stage name "Gia Scala," she made her motion picture debut in 1955. This came in All That Heaven Allows with Jane Wyman and Rock Hudson. However personal problems plagued her. In 1958 she attempted suicide. She landed roles in Tip On A Dead Jockey and The Garment Jungle in 1957 and The Tunnel of Love in 1958. The latter featured Richard Widmark and Doris Day. Critics acclaimed Gia's performance as a labor organizer in The Garment Jungle.
Later years and death
Having British citizenship because of her birth, she moved to work in film in England but there her troubles only escalated. Suffering from severe emotional problems, aggravated by alcohol, she made another unsuccessful suicide attempt before returning to Hollywood.
On the night of April 30, 1972, some friends found her dead in her Hollywood Hills home from an overdose of drugs and alcohol at age 38. Police said she had been taking medication for a drinking problem. Scala is interred in the Holy Cross Cemetery in Culver City, California.