November 4] 1877, Kyiv – died October 29, 1956, Washington DC) – was a Ukrainian diplomat, lawyer, active participant in Ukrainian and Jewish community and political affairs; attorney who became world-famous as the defense counsel for Mendel Beilis in the notorious Jewish blood libel trial in Kyiv from 1911 to 1913.

His father, David Margolin, was one of the leaders of the Jewish community in Kyiv for decades and one of the most prominent pioneers of the steamer business, and many branches of industries in Ukraine.

Arnold Margolin was active in several Ukrainian émigré scholarly institutions and promoted Ukrainian-Jewish mutual understanding.

"...Most important leaders of the American Slav Congress find many things in Soviet Russia superior to the situation in America," he wrote.

He noted the "close contact" between the USA-based American Slav Congress and the USSR-based All-Slav Committee.