Sir Geraint Llewellyn Evans CBE (16 February 1922 – 19 September 1992) was a Welsh bass-baritone noted for operatic roles including Figaro in Le nozze di Figaro, Papageno in Die Zauberflöte, and the title role in Wozzeck. Evans was especially acclaimed for his performances in the title role of Verdi's Falstaff. He sang more than 70 different roles in a career that lasted from his first appearance at Covent Garden in 1948 to his farewell there in 1984.

Evans was born in Cilfynydd, the only son of William John Evans (1899–1978), a coal miner, and his wife, Charlotte May, née Thomas (1901–1923). His family was Welsh speaking, and Evans spoke Welsh before he learned English.

On leaving school, aged 14, he worked as a window dresser for the High Class Ladies' Wear store in Pontypridd. He took singing lessons in Cardiff from Idloes Owen, who went on to found the Welsh National Opera, and sang with a local Methodist choir and the local amateur dramatic society. On the outbreak of World War II, he volunteered for the Royal Air Force; he was trained as a radio mechanic, but also took part in services entertainments.

After the war he worked for the British Forces Radio Network in Hamburg, where he sang with the radio chorus and took lessons from the baritone Theo Herrmann. He then studied with Fernando Carpi in Geneva and at the Guildhall School of Music and Drama in London first, for a short time, with Walther Gruner and then with Walter Hyde.

During a career that lasted from his first appearance at Covent Garden in January 1948 to his farewell at the same house in June 1984, Evans played over 70 roles. He made his operatic début as the nightwatchman in Die Meistersinger at the Royal Opera House in 1948 and performed there as Figaro in Mozart's The Marriage of Figaro in 1949, a part which he sang more than 500 times during his international career. It was as Figaro that he made his début at La Scala, Milan in 1960, the first British singer to appear there since the war.

His Vienna Staatsoper début as a last-minute replacement impressed Herbert von Karajan, who offered him a contract with the company, but Evans declined, believing that his place was at Covent Garden, which he always regarded as his operatic home; despite international success he always called himself "Sir David [Webster]'s boy."

At the Glyndebourne Festival Opera in 1957, he first played the part with which he became internationally associated: the title role in Verdi's Falstaff, which he later played in opera houses around the world, including Covent Garden (1961, directed and designed by Franco Zeffirelli), the Vienna Staatsoper and the Metropolitan Opera (1964 in another Zeffirelli production). Other roles in which he was celebrated were Beckmesser in Die Meistersinger, Figaro, Don Pizarro in Fidelio, the title role in Don Pasquale, Dulcamara in L'elisir d'amore and Leporello in Don Giovanni. He was an outstanding actor in both comic and tragic roles such as Wozzeck.

Evans's repertoire was in the bass-baritone range such as Don Pizarro, and in Mozart he chose the lower roles - Leporello rather than Don Giovanni, Figaro rather than the Count. Roles higher in the baritone register were not comfortable for him: he never undertook Iago in Otello and his one attempt at the title role in Rigoletto, at Covent Garden in 1964, ended in disaster when his voice failed on the first night, on which occasion he took the unusual step of apologising to the audience at the final curtain.