Simon Themstrup Michelet (8 February 1863 – 15 October 1942) was a Norwegian theologian.
He was born in Trondhjem as a son of customs officer Joseph Frantz Oscar Michelet (1832–1913) and Caroline Julie Laache (1833–1915). His grandfather was a brother of Christian Frederik Michelet and father of Carl Johan Michelet. On the paternal side he was a second cousin of major Christian Fredrik Michelet and politician Christian Fredrik Michelet. On the maternal side he was a first cousin of Søren Bloch Laache,
He grew up in Hitra and Trondhjem. He finished his secondary education in 1881, and decided to study theology. He was taken into the home of priest Johan C. H. Storjohann, where he met his future wife Marie Elisabeth Storjohann (1866–1951). They married in September 1888. Simon's sister was named Marie as well, and she married Elling Holst.
He graduated with the cand.theol. degree in 1887, and took the practical priest education in 1888. He also taught at the schools Aars og Voss and Trondhjem Cathedral School from 1887 to 1888. He studied further in Leipzig; first history of religion and Indian languages, then the theology of the New Testament. In 1894 he took the dr.theol. degree with the thesis Amos, oversat og fortolket on the Book of Amos. He worked as a teacher and priest until being appointed as a professor of theology in 1896. He was also a dean of the Faculty of Theology, and finally retired in 1933. He was also an editorial board member of 'Norsk Teologisk Tidsskrift from 1900 to 1926. He was a fellow of the Norwegian Academy of Science and Letters. Publications include Fra Moses til profetene (1915), Fra profetene til Jesus Kristus (1919) and Kristendom og rationalisme (1927). He also participated in a translation of the Old Testament.