John Leonard grew up in Washington, D.C., Jackson Heights, Queens, and Long Beach, California, where he graduated from Woodrow Wilson High School.

A political leftist, Leonard had an unlikely early patron in conservative leader William F. Buckley, who gave him his first job in journalism at National Review magazine in 1959.

Leonard went on to be Drama and Literature Director for Pacifica Radio flagship KPFA in Berkeley, where he featured a then-little-known Pauline Kael and served as the house book reviewer, delighting in the torrent of galleys sent him by publishers.

In 1975, he returned to the role of daily book reviewer, championing the work of women writers such as Maxine Hong Kingston and Mary Gordon.

He reviewed books for National Public Radio's Fresh Air and wrote a column for New York Newsday called "Culture Shock."

He was survived by his mother, Ruth, wife Sue, two children from his first marriage – Salon.com columnist Andrew Leonard[7] and Georgetown University history professor Amy Leonard[8] – and a stepdaughter, Jen Nessel,[9] who heads the communications department at the Center for Constitutional Rights, as well as three grandchildren: Tiana and Eli Miller-Leonard and Oscar Ray Arnold-Nessel.

He wrote definitive career essays on the work of writers ranging from Thomas Pynchon and Joan Didion to Eduardo Galeano, Salman Rushdie, Don DeLillo, Mary Gordon, John Cheever, Toni Morrison and Richard Powers.

He is too polite in ordinary conversations, with me at least, to set off the fireworks of all he knows and feels after reading and comparing and responding to, in the course of his long career as a literary critic, a thousand times more books than I have even heard of.