Samuel Leser Schwarz, known as Mommie was a Dutch Jewish painter and graphic artist. He also worked as a designer of book covers.

In 1920, he married Else Berg. Together they became an artistic couple and were part of the Bergen School of painters. Schwarz and Berg were both murdered at Auschwitz in 1942.

Schwarz was the tenth child of Leser Schwarz and Julie Winter. The family had eleven children. In 1897 he went with his brother Julius to New York City. In 1902 Mommie Schwarz returns to Europa and registered at the Academy of Fine Arts in Antwerp for the evening class of 1902–1903. On 26 March 1903 he unsubscribed at the academy and returned to New York where he arrived on 11 August 1903. In 1908 or 1909 Mommie left New York for Europe. Shortly afterwards he traveled to Berlin to visit his nephew Erich and his niece Else Berg. Subsequently, Else and Mommie traveled to Paris. In 1909 or 1910 he settled with Berg in the Netherlands.

In 1915 they moved to the town of Schoorl, where they established close ties with Leo Gestel and other artists from the Bergen School. The couple married in 1920 and moved to Amsterdam. From 1927 they lived adjacent to Amsterdam's Sarphatipark. By this time, Schwarz had cut all ties with Judaism. The couple traveled extensively, including trips to Mallorca, the former Yugoslavia, Turkey and Spain. After the German occupation of the Netherlands in World War II, they refused to go into hiding or to wear the Star of David. On 12 November 1942, they were arrested by the Germans and deported via the Westerbork transit camp to Auschwitz, where they were murdered immediately upon arrival on 19 November 1942.