Lipman (Lipmann) Jacob (born 1874, Friedrichstadt, Courland Governorate – died 1939, New Brunswick, USA) – soil scientist, biochemist, and public figure. Doctor of Philosophy (1903), Professor (1910).

Jacob Lipman settled in the United States in 1888. Lipman studied at the Baron de Hirsch Agricultural School in Woodbine (1894), then at Rutgers College (1898), and in 1903 graduated from Cornell University. Simultaneously (1898–1899), he worked at the New Jersey Agricultural Experiment Station (State of New York); from 1911 he served as its director. From 1902 he taught at Rutgers University and became Dean of the Faculty of Agronomy in 1915. Lipman was also director of the Jewish Agricultural Organisation.

In 1928, as a member of an expert commission, he visited the Land of Israel to examine the possibilities for establishing Jewish settlements there; in 1929 he became one of the non-Zionist members of the Jewish Agency.

Lipman’s principal scientific research concerned nitrogen, soil bacteria, and their influence on improving the fertility of cultivated land. He chaired the First International Congress of Soil Scientists (Washington, 1927) and headed the American delegation to the Third International Congress of Soil Scientists (Oxford, United Kingdom, 1935).

His brother, Charles Bernard Lipman, was a plant physiologist, Professor (1913) and Dean of one of the faculties of the University of California.