Manfred Lachs (21 April 1914 – 14 January 1993) was a Polish diplomat and jurist who served as a Judge of the International Court of Justice and greatly influenced the development of international law after World War II.

Right after his studies, he started working for the Consular Academy of Vienna and afterwards in the London School of Economics.

During the Second World War, Lachs escaped to London,[2] and served as secretary to Ignacy Schwarzbart, who was one of the two Jewish representatives on the National Council of the Polish government-in-exile.

[4] Before his career turned toward international law, he filled many judiciary posts in the Polish government such as Poland's Foreign Affairs director of the Department of treaties and legal jurisdiction (1947–1960) and prime minister's special advisor (1960–1967).

He later became a professor of international law at the University of Warsaw (1952–1993), and served as a member of the Polish delegation of the general assembly of the United Nations.