Birth Name: Joshua Thomas Radnor
Place of Birth: Columbus, Ohio, U.S.
Date of Birth: July 29, 1974
Ethnicity: Ashkenazi Jewish, as well as approximately 1/8th Irish, 1/8th possibly English
Josh Radnor is an American actor, writer, director, producer, and musician.
Josh’s paternal grandfather, who had Irish and probably English ancestry, likely converted to Judaism (Josh’s grandfather’s stepfather was Jewish). Josh’s three other grandparents were of Ashkenazi Jewish descent.
Josh was raised in Conservative Judaism, and attended an Orthodox Jewish school.
Josh’s paternal grandfather was Robert Clarence Radnor (born Clarence Rumbles, the son of Charles “Charlie” Rumbles and Mabel/Mable O’Donnell). Robert was born in Ohio. Charles was the son of Benjamin Rumbles and Martha Thomas, and probably had English ancestry. Mabel was the daughter of John O’Donnell and Mary or Betty Ryan, Canadians of Irish descent. Josh’s grandfather Robert Radnor was likely adopted by his stepfather, George Radnor, and took on his surname; George was born in Liverpool, England, to Jewish parents, Max Radnor, from Russia, and Leah Fleeter, from Hungary.
Josh’s paternal grandmother was Rose Faye Chester (born Rose Chenchinsky, the daughter of David Chenchinsky and Toba/Toby Woslow). Rose was born in Ohio, to Polish Jewish parents.
Josh’s maternal grandfather was named Charles B. Hirsch.
Josh’s maternal grandmother was Rose Altschuler (the daughter of Hyman Weinberg and Bessie Dworkin). Hyman was the son of Mayer Altshuler and Chana Sklar or Fiedler.
Sources: Genealogy of Josh Radnor – https://www.geni.com
Josh’s paternal grandfather, Robert Clarence Radnor, on the 1930 U.S. Census – https://familysearch.org
Josh’s paternal grandmother, Rose Chenchinsky, on the 1930 U.S. Census – https://familysearch.org
I doubt Charles “Charlie” Rumbles had primarly English ancestry.
This is him on Census: https://www.familysearch.org/ark:/61903/1:1:ML8Z-RD9
“Rumbles” is most likely the anglicization of a German surname (“Rommel”), and Thomas is usually Welsh.
75% Ashkenazi Jewish
25% Irish, other