Louis Homilius was a Russian organist, conductor, composer, and music educator of German origin. He was born on May 25, 1845, in Saint Petersburg, into a family of musicians. His father, Friedrich Homilius, was a horn player, music teacher, and composer, and gave him his first music lessons.
Homilius received his early education at a Reformed school and later studied at the Saint Petersburg Conservatory with Anton Rubinstein and Karl Davydov. He studied organ with Heinrich Stiehl.
From 1870, Homilius served as organist at the Lutheran Church of Saints Peter and Paul in Saint Petersburg. From 1871, he conducted the Peter and Paul Choral Society, giving annual concerts of sacred music by medieval and contemporary composers. He became a professor at the Saint Petersburg Conservatory, where he taught organ, succeeding his former teacher Stiehl. His students included Arthur Kapp, Rudolf Tobias, Miina Härma, and Peeter Süda.
Homilius wrote several choral works, songs, and short piano pieces. He died in Saint Petersburg on December 27, 1908, and was buried at the Volkov Lutheran Cemetery.