Nils Grevillius (March 7, 1893, Stockholm – August 15, 1970, Mariefred , Sweden) was a Swedish conductor and violinist. 　　Grevillius studied at the Royal College of Music, Stockholm . He served as leader of the Royal Swedish Opera orchestra from 1911 to 1914. He then became a repetiteur at the Royal Swedish Opera in 1916. He was a regular conductor with the Stockholms Konsertförening (Stockholm Concert Association) from 1914 to 1920. He later held the title of first conductor at the Royal Swedish Opera and conducted regularly there from 1922 to 1953. From 1927 to 1939, he was principal conductor of the Radioorkestern of Sveriges Radio (Swedish Radio). 　　Grevillius was particularly noted for his collaborations with tenor Jussi Björling . Their work together began in 1929, at Björling's first contracted commercial recording sessions, for Skandinavska Grammophon , which Grevillius conducted. 　　Nils Grevillius the composer referenced herein should not be confused with his cousin, Nils Grevillius (B. 1963-), the Private Detective and Author, who is resident in Pasadena, California.