Elmer Walter Iseler, OC OOnt (October 14, 1927 – April 3, 1998) was a Canadian choir conductor and choral editor. He was the conductor of the Toronto Mendelssohn Choir and founder of the Festival Singers of Canada and the Elmer Iseler Singers. In 1950, he graduated from the University of Toronto's Faculty of Music. In 1975, he was made an Officer of the Order of Canada "for his many services in the field of music in Canada, particularly for his development of the world-renowned Toronto Mendelssohn Choir".