In 1962, she won the Academy Award for Best Actress for her role in Two Women, becoming the first actress to win an Academy Award for a non-English-speaking performance. Loren has won 50 international awards, including two Oscars, five Golden Globe Awards, a Grammy Award and a BAFTA Award. Her other films include The Pride and the Passion (1957), Houseboat (1958), El Cid (1961), The Fall of the Roman Empire (1964), Man of La Mancha (1972), The Cassandra Crossing (1976), Prêt-à-Porter (1994), Grumpier Old Men (1995), and Nine (2009).

In 1999, Sophia Loren was listed by the American Film Institute on AFI's 100 Years... 100 Stars as one of 25 American female screen legends of all time. In 2002, she was honored by the National Italian American Foundation (NIAF) at its annual Anniversary Gala and was inducted into its Italian American Hall of Fame.

Loren was born at the Clinica Regina Margherita in Rome, the daughter of Romilda Villani (1914–1991) and Riccardo Scicolone, a construction engineer. Scicolone refused to marry Villani, leaving her, a piano teacher and aspiring actress, without support. Loren's parents had another child together, her sister Maria, in 1938. Loren also has two younger half-brothers, Giuliano and Giuseppe, on her father's side. Romilda, Loren, and Maria lived with Loren's grandmother in Pozzuoli, near Naples, to survive.

During World War II, the harbor and munitions plant in Pozzuoli was a frequent bombing target of the Allies. During one raid, as Loren ran to the shelter, she was struck by shrapnel and wounded in the chin. Subsequently, the family moved to Naples and begged distant relatives to take them in.

After the war, Loren and her family returned to Pozzuoli. Grandmother Luisa opened a pub in their living room, selling homemade cherry liquor. Villani played the piano, Maria sang and Loren waited tables and washed dishes. The place was very popular with the American GIs stationed nearby.

When she was 14 years old, Loren entered a beauty contest in Naples and, while not winning, was selected as one of the finalists. Later she enrolled in acting class and was selected as an extra in Mervyn LeRoy's 1951 film, Quo Vadis, launching her career as a motion picture actress. She eventually changed her name to Sophia Loren.

After being credited professionally as Sofia Lazzaro, she began using her current stage name in 1952's La Favorita. Her first starring role was in Aida (1953), for which she received critical acclaim. After playing the lead role in Two Nights with Cleopatra (1953), her breakthrough role was in The Gold of Naples (1954), directed by Vittorio De Sica. Too Bad She's Bad, also released in 1954, became the first of many films in which Loren co-starred with Marcello Mastroianni. Over the next three years she acted in many films such as Scandal in Sorrento (1955) and Lucky to Be a Woman (1956). In 1957, Loren's star had begun to rise in Hollywood, with the films Boy on a Dolphin (her U.S. film debut), Legend of the Lost with John Wayne, and The Pride and the Passion in which she starred opposite Cary Grant and Frank Sinatra.

Loren became an international film star with a five-picture contract with Paramount Pictures in 1958. Among her films at this time were Desire Under the Elms with Anthony Perkins, based upon the Eugene O'Neill play; Houseboat, a romantic comedy co-starring Cary Grant; and George Cukor's Heller in Pink Tights, in which she appeared as a blonde for the first time.

In 1961, she starred in Vittorio De Sica's Two Women, a stark, gritty story of a mother who is raped while trying to protect her daughter in war-torn Italy. Originally cast as the daughter, Loren fought against type and was re-cast as the mother (actress Eleonora Brown would portray the daughter). Loren's performance earned her many awards, including the Cannes Film Festival's best performance prize, and an Academy Award for Best Actress, the first major Academy Award for a non-English-language performance and to an Italian actress.

Loren is known for her sharp wit and insight. One of her most frequently-quoted sayings is her quip about her famously-voluptuous figure: "Everything you see, I owe to spaghetti." However, on the December 20, 2009, episode of CBS News Sunday Morning, Loren denied ever saying the line.