Tobias Dantzig (/ˈdæntsɪɡ/; February 19, 1884 – August 9, 1956) was a Russian-American mathematician, the father of George Dantzig, and the author of Number: The Language of Science (A critical survey written for the cultured non-mathematician) (1930) and Aspects of Science (New York, Macmillan, 1937).
Born in Shavli[1][2] (then Imperial Russia, now Lithuania) into the family of Shmuel Dantzig (?-1940) and Guta Dimant (1863–1917), he grew up in Łódź and studied mathematics with Henri Poincaré in Paris.
Tobias married a fellow Sorbonne University student, Anja Ourisson, and the couple emigrated to the United States in 1910.
He worked for a time as a lumberjack, road worker, and house painter in Oregon, until returning to academia at the encouragement of Reed College mathematician Frank Griffin.
He was the father of George Dantzig, a key figure in the development of linear programming.