Gildenhorn was born September 17, 1929 in Washington, D.C., to Oscar, a retail grocer, and Celia Gildenhorn. Both of his parents were born in the Russian Empire (presently Poland) and immigrated to the United States in the early 20th century.
In 1956, Gildenhorn and high school friends Donald Brown and Gerald Miller founded a law firm. In 1962, they became real estate developers in the Washington, D.C. area forming what later became JBG Smith.[4]
Gildenhorn was married to Alma Lee Gross, whom he met while a student at the University of Maryland. They had two children: Carol Winer and Michael Gildenhorn.[3]
Gildenhorn was a financial supporter of John F. Kennedy Center for the Performing Arts[7] and the Institute for Bone and Joint Health of Sibley Memorial Hospital.[8] He also endowed the University of Maryland’s Gildenhorn Institute for Israel Studies and the Gildenhorn Recital Hall at The Clarice Smith Performing Arts Center.[3]
Gildenhorn died in Washington D.C. on October 21, 2023, at the age of 94.[9]