Riva won the BAFTA Award and the César Award for her lead role in Michael Haneke's Amour as Anne Laurent, and was nominated for the Academy Award for the same role. She had previously been nominated for a BAFTA Award for Hiroshima mon amour, and had won Best Actress at the Venice Film Festival for Thérèse Desqueyroux (1962).
Riva was born Paulette Germaine Riva on 24 February 1927 in Cheniménil, France, the daughter of Jeanne Fernande (née Nourdin), a seamstress, and René Alfred Riva, a sign painter from Italy.
Growing up in Remiremont, Riva showed an early passion for acting, performing in plays at her local theatre, but worked for several years as a seamstress. After seeing an advertisement on a local newspaper, Riva applied to an acting school in Paris.
At the age of 26, she moved to the French capital to pursue a career in acting despite objections from her family. In 1954, she performed her first role on stage in a Paris production of George Bernard Shaw's Arms and the Man. In 1957, Riva made her onscreen acting debut in the TV series Énigmes de l'histoire.
Riva was cast as one of the leads in Hiroshima mon amour (1959), a film directed by Alain Resnais and written by Marguerite Duras, in which she played a French actress having an affair with a Japanese architect (Eiji Okada) in Hiroshima. Her performance gained a BAFTA Award nomination for Best Foreign Actress in 1960. Later she appeared in Gillo Pontecorvo's Kapò (1960), Jean-Pierre Melville's Léon Morin, Priest (1961) and Georges Franju's Thérèse Desqueyroux (1962), for which she won the Volpi Cup for Best Actress at the 23rd Venice International Film Festival. Riva also appeared in Krzysztof Kieślowski's Three Colors: Blue (1993), Tonie Marshall's Venus Beauty Institute (1999) and Julie Delpy's Skylab (2011).
Riva starred in the well received Michael Haneke film Amour (2012) with Jean-Louis Trintignant, playing an elderly music teacher being cared for by her husband following a series of debilitating strokes. She won the BAFTA Award for Best Actress in a Leading Role in 2013 for her performance, and was nominated for the Academy Award for Best Actress. Riva travelled to the 85th Academy Awards ceremony, which was held on her 86th birthday, but Jennifer Lawrence won for Silver Linings Playbook instead. At the age of 85 when she was nominated, Riva was the oldest ever Best Actress nominee, and the second-oldest acting nominee after Gloria Stuart, who was 87 years old when she was nominated for Titanic (1997).
Riva had an extensive theatre career in Paris. In 2001, she performed in Medea at the Festival d'Avignon. She appeared occasionally on French television. Riva returned to the Paris stage in February 2014, co-starring with Anne Consigny in the Marguerite Duras play Savannah Bay at the Théâtre de l'Atelier.
While filming Hiroshima mon amour, Riva photographed Hiroshima; a half-century later these photographs were exhibited at the Nikon Salon and were issued in book form in France and Japan. Riva was a published poet.
Riva led a private life, never married and had no children. She had a partner, who died in 1999. Riva owned a fourth-floor walk-up apartment in the Latin Quarter of Paris, and had lived there for more than half a century.
Riva died from cancer on 27 January 2017 in Paris four weeks before her 90th birthday. A memorial service was held for Riva on 4 February 2017 at Saint-Germain de Charonne church in the 20th arrondissement of Paris; she was then buried in Charonne cemetery.