Harry Morris Warner (December 12, 1881 – December 27, 1958) was an American studio executive, one of the founders of Warner Bros., and a major contributor to the development of the film industry. Along with his three brothers (Albert, Sam and Jack) Warner played a crucial role in the film business and played a key role in establishing Warner Bros. Pictures, Inc, serving as the company president until 1956.

Warner was born Hirsch Moses "Wonsal" or "Wonskolaser" to a family of Polish Jews from the village of Krasnosielc. The village was a short distance from Warsaw in the part of Poland that had been subjugated to the Russian Empire following the 18th-century partitions of the Polish-Lithuanian Commonwealth. He was the son of Benjamin Wonsal, a shoemaker born in Krasnosielc, and Pearl Leah Eichelbaum. His given name was Moses but he was called Hirsch in the United States. In October, 1889, he came to Baltimore, Maryland with his mother and siblings on the steamship Hermann from Bremen, Germany. Their father had preceded them, immigrating to Baltimore in 1883 or 1885 in order to pursue his trade in shoes and shoe repair. It was at that time that he changed the family name to Warner which was used thereafter. As in many Jewish immigrant families, some of the children gradually acquired anglicized versions of their Yiddish-sounding names. Hirsch became Harry, and his middle name Morris was likely a version of Moses.

A Polish American (Polish: Amerykanin polskiego pochodzenia), is a citizen of the United States of Polish descent. There are an estimated 10 million Polish Americans, representing about 3.2% of the population of the United States. No distinction is made in the American census between ethnically Polish Americans and descendants of non-ethnic Poles, such as Jews or Ukrainians, who were born in the territory of Poland and considered themselves Polish nationals. Therefore, some say, of the 10 million Polish Americans, only a certain portion are of Polish ethnic descent. On the other hand, many ethnic Poles when entering the US from 1795–1917, when Poland did not exist, did not identify themselves as ethnic Poles and instead identified themselves as either German, Austrian or Russian (this pertained to the nations occupying Poland from 1795–1917). Therefore, the actual amount of Americans of at least partial Polish ancestry, could be well over 10 million. Polish Americans are the largest European ethnic group in the United States of Slavic origin.