Ernest Klein (1899 - February 4, 1983) was a Canadian linguist, author, and rabbi.

Born in Satmari, Siebengebirgen, Romania, he received his PhD at the University of Vienna in 1925. He was the rabbi of the Nové Zámky community, Slovak Republic, from 1929 to 1944. In 1944, he was deported to Auschwitz and later to Dachau, where he was liberated. After the war he served as rabbi in Satmari. After emigrating to France, he was a rabbi of the synagogue on Rue de Montevideo in Paris (1950-1951) and in 1952 he emigrated to Canada, where he held the post of Rabbi of Congregation Beth Yitshak in Toronto until his death.

He is the author of A Comprehensive Etymological Dictionary of the English Language (1966-1967).

In 1978 he was made an Officer of the Order of Canada.