Nina Grieg, born Hagerup (November 24, 1845 – December 9, 1935) was a Danish-Norwegian lyric soprano. She was the first cousin of composer Edvard Grieg, whom she married.
Nina was born in Bergen, Norway. She married Edvard on June 11, 1867, in Copenhagen. The couple often performed concerts together in Europe, usually to rave reviews. Edvard considered her the best performer of his songs.
The English composer Frederick Delius dedicated two sets of songs to her in the years 1888–1890.
She was featured as a soloist in Felix Mendelssohn's Elijah with Musikselskabet Harmonien (later known as the Bergen Philharmonic Orchestra) in 1866.
After the death of Edvard in 1907, she moved to Denmark where she died twenty eight years later.
Nina Grieg never recorded professionally, but two amateur recordings made on wax cylinders have been preserved (sadly in quite poor condition) and have been issued on the Simax label.