Régine Crespin (23 February 1927 – 5 July 2007) was a French singer who had a major international career in opera and on the concert stage between 1950 and 1989. She started her career singing roles in the dramatic soprano and spinto soprano repertoire, drawing particular acclaim singing Wagner and Strauss heroines. She went on to sing a wider repertoire that embraced Italian, French, German, and Russian opera from a variety of musical periods. In the early 1970s Crespin began experiencing vocal difficulties for the first time and ultimately began performing roles from the mezzo-soprano repertoire. Throughout her career she was widely admired for the elegance, warmth and subtlety of her singing, especially in the French and German operatic repertories.
Crespin began her career in France, earning her first critical successes in the French provinces during the early 1950s and then becoming a fixture at the Opéra National de Paris in the mid-1950s. Her international career was launched in 1958 with a critically acclaimed performance of Kundry in Richard Wagner's Parsifal at the Bayreuth Festival. She soon appeared at most of the major opera houses in the United States and Europe and made a number of appearances in South America as well. She had a long and fruitful association with the Metropolitan Opera in New York City, making over 125 appearances at that house between 1962 and 1987. Crespin retired from the stage in 1989, after which she taught singing for many years at her alma mater, the Conservatoire de Paris, and gave numerous acclaimed master classes at conservatories and universities internationally.
In recognition of Crespin's artistry as a singer, the Marguerite Long–Jacques Thibaud Competition, which had been restricted to pianists and violinists, was expanded in 2011 to include singers, and renamed the Long-Thibaud-Crespin Competition.