Clelia Maria Giuseppa (Giuseppina) Strepponi (Lodi, 8 September 1815 – Villanova sull'Arda, 14 November 1897) was a nineteenth-century Italian operatic soprano of great renown and the second wife of composer Giuseppe Verdi.

She is often credited with having contributed to Verdi's first successes, starring in a number of his early operas, including the role of Abigaille in the world premiere of Nabucco in 1842. A highly gifted singer, Strepponi excelled in the bel canto repertoire and spent much of her career portraying roles in operas by Vincenzo Bellini, Gaetano Donizetti, and Gioachino Rossini, often sharing the stage with tenor Napoleone Moriani and baritone Giorgio Ronconi. Donizetti wrote the title role of his opera Adelia specifically for Strepponi. She was described as possessing a "limpid, penetrating, smooth voice, seemly action, a lovely figure; and to Nature's liberal endowments she adds an excellent technique"; her "deep inner feeling" was also lauded.

Both her personal and professional life were complicated by overwork, by at least three known pregnancies, and by her vocal deterioration which caused her to retire from the stage by the age of 31, in 1846 when she moved to Paris to become a singing teacher. While it is known that she had a professional relationship with Verdi from the time of his first opera, Oberto in 1839, they became a couple by 1847 when they lived together in Paris, then moved to Busseto in 1849, married in 1859, and remained together until the end of her life.

Strepponi was born in the city of Lodi in the Lombard region of Italy. She was the oldest child of Rosa Cornalba and Feliciano Strepponi (1797–1832), who was the organist at Monza Cathedral and a moderately successful opera composer, his works having been performed in theatres in Milan, Turin and Trieste. Her first music lessons were with her father who focused mainly on teaching her to play the piano, but in 1830 she was enrolled in the Milan Conservatory although just over the age of 15. After her father's death at the age of 35 in 1832 of encephalitis, she was able to continue studying singing and the piano as a non-paying pupil at the Conservatory where she notably won first prize for bel canto during her final year in 1834. Her performance of the cavatina from Beatrice di Tenda and for her parts in both a duet and a trio brought mention in the Gazzetta privilegiata di Milano of 29 September 1834, where it was noted that her vocal qualities, "will be a fine acquisition, when the time comes, for the Italian stage".

Strepponi made her professional opera début in December 1834 as Adria in Luigi Ricci's Chiara di Rosembergh at the Teatro Orfeo. She had her first major success during the following spring at the Teatro Grande in Trieste singing the title role in Rossini's Matilde di Shabran.

This success quickly led to numerous engagements at major opera houses throughout Italy and Giuseppina soon became her family's major breadwinner. In the summer of 1835, she went to Austria to sing Adalgisa in Bellini's Norma and Amina in Bellini's La sonnambula at the Theater am Kärntnertor in Vienna where she was praised highly by audiences and critics. Although she was highly talented, she never sang outside Italy after 1835.

Strepponi became a celebrity among opera singers during the late 1830s, arousing fanatical enthusiasm in performances throughout Italy. In 1836 she sang the roles of Ninetta in Rossini's La gazza ladra, Elvira in Bellini's I puritani, and the title role in Rossini's La Cenerentola at the Teatro La Fenice in Venice.

In Spring 1837, she went under contract with Alessandro Lanari of Florence, then known as "the king of impresarios", who was able to secure important engagements for her in the years following. However, within a very short time, she found herself pregnant and had to sing through three pregnancies during the time with Lanari.