Sissel Kyrkjebø (Norwegian pronunciation: [ˈsɪsəl ˈçʏʁçəˌbʷøː], /ˈsisel ˈçyrçeˌbø/; born 24 June 1969), also simply known as Sissel, is a Norwegian soprano.

Sissel is considered one of the world's top crossover sopranos, her musical style ranges from pop recordings and folk songs, to classical vocals and operatic arias. She possesses a "crystalline" voice and wide vocal range, sweeping down from mezzo-soprano notes, in arias such as Mon cœur s'ouvre à ta voix from Saint-Saëns's opera Samson et Dalila, to the F natural above soprano C. She sings mainly in English and Norwegian, and has also sung songs in Swedish, Danish, Irish, Italian, French, Russian, Icelandic, Faroese, German, Neapolitan, Māori, Japanese, and Latin.

She is well known for singing the Olympic Hymn (Hymne Olympique) at the opening and closing ceremonies of the 1994 Winter Olympics in Lillehammer, Norway; for duets with Plácido Domingo, Charles Aznavour, José Carreras, Neil Sedaka, Warren G, Brian May, Bryn Terfel, Josh Groban, Diana Krall, Russell Watson and The Chieftains; and her participation on the Titanic film soundtrack.

Sissel received her first U.S. Grammy nominations on 6 December 2007 for a collaboration with the Mormon Tabernacle Choir. Spirit of the Season, a collection of songs from the choir's 2006 Christmas concert at Temple Square, was nominated for the Best Classical Crossover Album of the Year, as well as Best Engineered Classical Album.

Sissel's combined solo record sales (not including soundtracks and other albums to which she contributed) amount to 10 million albums sold, most of them in Norway, a country with 5 million people. Her albums have also sold well in Sweden, Denmark and Japan. Together with Odd Nordstoga, they are the only Norwegian artists to have an album go 11 times platinum in album sales for Strålande jul" (Glorious Christmas).

The first name 'Sissel' is a Norwegian variant of 'Cecilia'. This is a popular first name from Saint Cecilia, the patron saint of church music.