Farah worked for six years as executive news editor at the Los Angeles Herald Examiner. On July 22, 1990, Farah became editor of the Sacramento Union. The paper had been losing up to $3 million annually, and in early 1990 it was purchased from Richard Mellon Scaife by Daniel Benvenuti Jr. and David Kassis. Farah and the paper's owners envisioned the paper as a conservative alternative to the Sacramento Bee. "We just thought the way to go was to be unabashedly conservative in our approach," explained Farah to the Washington Post. Among other things, Farah convinced Rush Limbaugh to write a daily column, which ran on "Page 1."
He launched the online WorldNetDaily in 1997. He has published some controversial material there, such as in 2003 applauding a wife's murder of her husband for alleged infidelity.
Farah is among those who have promulgated conspiracy theories questioning Barack Obama's status as a natural born citizen of the United States and resultant eligibility to serve as U.S. President, stating, "It'll plague Obama throughout his presidency. It'll be a nagging issue and a sore on his administration, much like Monica Lewinsky was on Bill Clinton's presidency" and "It's not going to go away, and it will drive a wedge in an already divided public." Despite the release of Obama's notarized birth certificate abstract, Farah demanded that Obama release his "long-form" birth certificate, which was subsequently posted on the White House's web site on April 27, 2011. Farah had previously pledged $15,000 to the hospital where Obama was born upon the release of said document. When Obama finally released the long-form birth certificate, he called it "fraudulent," and disowned the pledge. 
^ abWilliam Trombley (May 16, 1991). "Paper Chase; Media: The Sacramento Union is Trying to Attract Readers and Advertisers by Billing Itself as 'Pro-American,' 'Pro-Life,' and 'Pro-Business.'". Los Angeles Times.
^Pat Guy (July 13, 1990). "New editor for 'Sacramento Union'". USA Today.
^ abHoward Kurtz and Charles Trueheart (October 23, 1990). "At Sacramento Union, A Conservative Bent". Washington Post.
^Dorothy Giobbe (September 17, 1994). "Western Journalism Center director says it's non-partisan, not pro-right wing". Editor & Publisher.
^Mark O'Keefe (November 24, 2002). "Conservative media flex muscles". The Star-Ledger (Newark).
^The Occidental Quarterly, Volume 6, Number 2, Summer 2006, pages 9–37 "Sexual Utopia in Power" by F. Roger Devlin – Page 23's Modern Chivalry: "Joseph Farah of World Net Daily commends a wife for murdering her unfaithful husband." in reference to FREE CLARA HARRIS! published January 30, 2003 by Joseph Farah: "Clara Harris hit the gas on her Mercedes and ran over Harris, shearing the passenger door right off the home wrecker’s Navigator. She ran over him a few more times to make sure he was dead .. I say: Free Clara Harris. We need more women like her. Live like her .. I would find Clara Harris not guilty. After she was sprung, I’d give her a medal. She did the world a favor .. she did the right thing. That creep deserved what he got .. Free her and let her be an example to every cheating husband and wife in America. There is a price to pay. Sometimes it’s the ultimate price."