Nina Grieg, née Hagerup (24 November 1845 – 9 December 1935) was a Danish–Norwegian lyric soprano.

Her parents were the malt inspector Herman Didrik Hagerup and the actress Luise Adeline Werligh, née Falck.

[2] She was featured as a soloist in Felix Mendelssohn's Elijah with Musikselskabet Harmonien (later known as the Bergen Philharmonic Orchestra) in 1866.

[3] The English composer Frederick Delius dedicated two sets of songs to her in the years 1888–1890.

She married her first cousin, Norwegian composer Edvard Grieg, on 11 June 1867, in Copenhagen, Denmark.