Dag Ivar Wirén (Örebro, October 15, 1905 – Danderyd, April 19, 1986) was a Swedish composer. Wiren studied at the at the Stockholm conservatory from 1926-1931, and in 1932 won the state stipend. He used the award money to continue his studies in Paris, where he remained for three years. Upon his return to Sweden, he took up work as a music critic, and composed his first two symphonies. His most famous work is his Serenade for Strings (1937), but he also composed 5 symphonies, string quartets, and numerous orchestral pieces and film scores.