Line Tjørnhøj (born 1960) is a Danish composer. She describes the voice as basic to the human sound universe with its immediate access to our ears and emotions. She typically deals with timeless problems and emotions via stories from our own time. She is well known for dealing with cruel subjects where men and women are challenged to the utmost as a consequence of the misuse of power in its various forms. She exploits the soothing quality and beauty of the voice to establish a space for the impossible and painful stories she has narrated in the course of her career as a composer. She works collaboratively with the performers for which her works are created, insisting that the individual elements of a performance are all interrelated.Tjørnhøj studied composition at The Royal Academy of Music in Aarhus with Simon Steen-Andersen, Niels Rønsholdt and Lasse Laursen.
In 2025 Line Tjørnhøj was awarded the lifelong honorary grant from the Danish Arts Foundation, celebrating the Danish artists who create art of outstanding quality. She has received the prestigious Carl Nielsen and Anne Marie Carl-Nielsen Foundation's Honorary Award Prize (2017), the three year working grant from the Danish Arts Foundation and the Danish Composers’ Society Grant among others. Her opera Anorexia Sacra was awarded best chamber opera by the American Opera Vista Festival, 2009.
Her works have been played by renowned ensembles and orchestras such as the Danish National Symphony Orchestra, Danish National Girls' Choir, Theatre of Voices, Göteborg Operan, Aarhus Symphony Orchestra, Ars Nova Copenhagen, Ensemble Lydenskab, Esbjerg Ensemble and Aarhus Chamber Orchestra amongst others.