Saul Lowenstam (1717 – 19 June 1790) was a renowned Dutch rabbi and talmudist.
Saul Lowenstam was born in 1717 in Rzeszów to his parents Aryeh Leib ben Saul (who was the rabbi in Rzeszów at the time) and Miriam the daughter of the Chacham Tzvi. He married Hendele, the daughter Abraham Kahana, who was rabbi of Grodno, Ukraine. His first rabbinical position was in Lokachi, Ukraine (located in the Lokachi Raion and named Lakacz in Yiddish), followed by Dubno, where he succeeded his father-in-law.
After the death of his father in 1755, Lowenstam succeeded him as the Chief Rabbi of Amsterdam, Netherlands. Lowenstam died in Amsterdam on 19 June 1790. He was succeeded as Chief Rabbi by his son, Jacob Moses Lowenstam.
Lowenstam was the author of the Binyan Ariel published in Amsterdam 1778. He also authored a Torah Commentary HeChatzer HaChadasha published in Amsterdam in 1768. A pamphlet titled Halacha Lema'aseh Rav published in Amsterdam in 1828 contains his 1783 halachic ruling asserting the kashrut of Dutch cheese.
- Samuel Israel Mulder (1851). Iets over de Begraafplaatsen der Nederlandsch-Israëlitische Gemeente te Amsterdam, en bijzonder over die te Muiderberg, met eene opgave van twintig grafschriften. Amsterdam, Netherlands: van Embden & Co. p. Avnai Zikaron Section, No. 6, pp 12. OCLC 47167332.
- Deutsch, Gotthard; E. Slijper. "LÖWENSTAMM, SAUL". Jewish Encyclopedia. Retrieved 21 September 2010.
- Bleich, J. David (1989). Contemporary Halakhic Problems; Volume 16. KTAV Publishing House. pp. 63–4. ISBN 978-0-88125-315-3.
- Rosenstein, Neil (1990). The Unbroken Chain: Biographical Sketches and the Genealogy of Illustrious Jewish Families from the 15th-20th Century, Volume 2. CIS Publishers. p. 822. ISBN 978-0-9610578-4-8.
- Saul Lowenstam (1828). Halacha Lema'aseh Rav הלכה למעשה רב. Amsterdam, Netherlands: David son of Jacob Proops. OCLC 644884598.