Brenner was born into an Orthodox Jewish family. He became an atheist at age 10 or 12 and a Marxist at age 15. Brenner's involvement with the American Civil Rights Movement began when he met James Farmer of the Congress of Racial Equality, later the organizer of the "freedom rides" of the early 1960s. He also worked with Bayard Rustin, later the organizer of Martin Luther King's 1963 "I Have a Dream" march on Washington. (Neither were Marxists.)
Brenner was arrested three times during civil rights sit-ins in the San Francisco Bay Area. He spent 39 months in jail when a court revoked his probation for marijuana possession, because of his activities during the Berkeley Free Speech Movement at the University of California in 1964.
He was an anti-war activist from the first days of the Vietnam War, speaking frequently at rallies in the Bay Area. In 1963 he organized the Committee for Narcotic Reform in Berkeley. In 1968 he co-founded the National Association for Irish Justice, the American affiliate of the Northern Ireland Civil Rights Association.
In the 1990s, he and Kwame Ture (aka Stokely Carmichael), the legendary "Black Power" leader of the Student Non-Violent Coordinating Committee, co-founded the Committee against Zionism and Racism. They also published The Anti-War Activist.
In 2003, Brenner spoke at the inaugural meeting of Jews Against Zionism in, with his colleagues Alice Coy, Haim Bresheeth and Roland Rance who presented Brenner's book, "51 Documents: Zionist Collaboration with the Nazis".
Brenner is the author of four books: Zionism in the Age of the Dictators, The Iron Wall: Zionist Revisionism from Jabotinsky to Shamir, Jews in America Today, and The Lesser Evil, a study of the Democratic Party. His books have been widely translated, and have been reviewed in 11 languages, to markedly mixed reviews. His books have received very positive reviews from the London Times, the London Review of Books, Booklist magazine, the Washington Report on Middle East Affairs, among many other publications. A new edition of Zionism in the Age of the Dictators is scheduled for release in early 2014 from On Our Own Authority! Publishing.
His articles have also appeared in The Nation, Amsterdam News, Jewish Guardian, Atlanta Constitution, Washington Report on Middle East Affairs, Middle East Policy, Middle East International, Journal of Palestine Studies, New Statesman, Al-Fajr and United Irishman.
In 2002, he edited 51 Documents. It contains complete translations of many of the documents quoted in Zionism in the Age of the Dictators and The Iron Wall. This book has been translated to Spanish by Luis César Bou as 51 Documentos Sobre la Colaboración Sionista con los Nazis Editorial Canaán, Buenos Aires, 2012. In 2004, he edited Jefferson & Madison On Separation of Church and State: Writings on Religion and Secularism.
In 2013, Brenner co-authored Black Liberation and Palestine Solidarity with historian Matthew Quest. The book is a collection of selected essays that "discusses the historical response of African American freedom movements to the colonial settler state of Israel and its role in American Imperialism in the Middle East." Michael Letwin, co-founder of Labor For Palestine and Jews For Palestinian Right Of Return, has called Black Liberation and Palestine Solidarity “An informative, incisive, and essential historical analysis of the African American freedom movement’s solidarity with Palestine.”
Brenner is said to be working on a memoir, tentatively called The World's Grouchiest Marxist.
- Lenni Brenner: biographical details
- Zionism in the Age of the Dictators has been translated into Japanese: Fuashizumu jidai no shionizumu, by Shiba Kensuke (芝健介), Hosei Daigaku 2001, German (in a revised edition), as Zionismus und Faschismus : über die unheimliche Zusammenarbeit von Zionisten und Faschisten, tr. Verena Gajewski Homilius, Kai, Berlin 2007, and Spanish as Sionismo y Fascismo, by Luis César Bou, Bósforo Libros, Madrid,2010,
- Lenni Brenner, 51 Documents, December 23, 2002] in CounterPunch
- Lenni Brenner and Matthew Quest, Black Liberation and Palestine Solidarity. (Atlanta: On Our Own Authority! Publishing, 2013).
- Lenni Brenner. Beyond the UN's Rhetoric: Holocaust History, CounterPunch, January 29, 2005.
- Lenni Brenner. The plot to stigmatize "51 Documents" on Amazon.com, CounterPunch, May 25, 2005.
- "It's All Rabbis and No Jews": An Interview with Lenni Brenner
- Interview with Lenni Brenner by JK Fowler for The Mantle March 19, 2011