Max Weinreich was born Meyer Lazarevich Veynreykh to a Jewish family in Kuldiga, in the German-speaking region of Courland, now in Latvia, then part of the Russian Empire. He became interested in the Yiddish language as a teenager. After attending local schools, he went to a private Jewish gymnasium (high school) for boys in St. Petersburg and St. Petersburg University. He did graduate studies in linguistics at Marburg University in Germany, where he earned his doctorate in 1923. That same year, he published Shtaplen (Rungs), a collection of essays in Yiddish. In 1925, he became the co-founder of the YIVO Institute for Jewish Research (YIVO being the Yiddish acronym for Jewish Scientific Institute) based in his home in Vilnius, Lithuania, then part of Poland. He was in Denmark with his older son on their way to a linguistics conference when World War II began. They went to the USA, where he was reunited with his wife Regina Shabad Weinreich and their younger son in 1940. Settling in New York City, Weinreich became a professor of Yiddish at City College of New York and re-established YIVO.
He published a number of books on linguistics, history, and economics in Yiddish, and edited YIVO’s short-lived popular journal, Yidish far ale, and its general academic journal, YIVO-bleter. His study of German academic collaboration with the Nazis, Hitler’s Professors, appeared in English in 1946. His monumental, four-volume Geshikhte fun der yidisher shprakh (History of the Yiddish Language), completed shortly before his death, was published posthumously by YIVO in 1973. He also translated Sigmund Freud and Ernst Toller into Yiddish.