Christa Ludwig (16 March 1928 – 24 April 2021) was a German mezzo-soprano and sometime dramatic soprano, distinguished for her performances of opera, lieder, oratorio, and other major religious works like masses, passions, and solos in symphonic literature. Her performing career spanned almost half a century, from the late 1940s until the early 1990s.

She sang at many international opera houses and festivals, including at the Vienna State Opera from 1955 to 1994, and at the Metropolitan Opera in many roles. She is remembered for roles such as Mozart's Dorabella, Beethoven's Leonore in Fidelio, Wagner's Kundry, and both Octavian and the Marschallin in Der Rosenkavalier by Richard Strauss. In Vienna, she created the title role of Gottfried von Einem's Der Besuch der alten Dame in 1971.

She is widely recognised as having been one of the most significant and distinguished singers of the 20th century. The NPR Listener's Encyclopedia of Classical Music (2006) stated "Ludwig possessed a voice of exquisite richness and, when needed, breathtaking amplitude. She had the ability to impart dramatic urgency to a performance, the hallmark of a great singer."