Fred S. Karger (born January 31, 1950) is an American political consultant, gay rights activist and watchdog, and former actor. His unsuccessful candidacy for the Republican nomination for the 2012 US presidential election made him the first openly gay presidential candidate in a major political party in American history. Karger has worked on nine presidential campaigns and served as a senior consultant to the campaigns of Presidents Ronald Reagan, George H. W. Bush and Gerald Ford.

Karger was a partner at the Dolphin Group, a California campaign consulting firm. He retired after 27 years and has since worked as an activist on gay rights causes, from unsuccessfully attempting to protect the gay bar The Boom to using his organization Californians Against Hate to investigate the Church of Jesus Christ of Latter-day Saints (LDS Church) and the National Organization for Marriage's campaigns to repeal the state's same-sex marriage law.

Karger was born in Glencoe, Illinois, the son of Jean (née Foreman), an active community volunteer, and Robert S. Karger, who owned a brokerage firm. Karger graduated from New Trier High School in 1968 and earned a B.A. in speech communications from the University of Denver in 1972.

Karger moved to Los Angeles from Chicago and began acting. He appeared in a John Hughes-directed Edge Shave Cream commercial, as well as featured roles in Owen Marshall: Counselor at Law; Rich Man, Poor Man; Horshack! (a pilot for a spinoff from Welcome Back Kotter); and Airport 1975. However, Karger continued to follow his passion for politics, and eventually landed with the Dolphin Group in 1977.

Karger's political career began with the Dolphin Group in 1977. He served as executive vice president and chief financial officer through 2004. During his tenure, Karger helped lead the campaigns of California Governor George Deukmejian, Lt. Governor Mike Curb, the presidential campaigns of Senator Robert Dole (R-KS), Senator Paul Laxalt (R-NV), Governor John Connally (R-TX), Senator Charles Percy (R-IL) and dozens of other federal, state and local candidates. He managed statewide and local ballot measure campaigns, judicial campaigns, and served on several campaign finance and steering committees.

Karger consulted on behalf of real estate developers, farmers, consumer product companies, the hospitality industry, and other businesses in their dealings with local, state and the federal government.

On April 10, 2010, Karger held a press conference at the Southern Republican Leadership Conference (SRLC) in New Orleans, to announce that he was "seriously considering becoming a candidate for President of the United States in 2012 as an Independent Republican." He attended the SRLC with other potential candidates for the Republican presidential ticket such as Sarah Palin, Ron Paul, Rick Santorum, Newt Gingrich and Gary Johnson. This was the day after GOP presidential candidate Mitt Romney announced forming his 2012 exploratory committee; Karger declared himself the "Anti-Romney" candidate, and later stated that he "plans to run a campaign specifically designed to throw a wrench into Romney's run." After making the announcement, Karger traveled to Iowa and New Hampshire several times, holding town hall meetings, talking to voters, as well as meeting with political, LGBTQ, AIDS organization leaders, and the media.

On July 18, 2010, Karger announced he had formed an exploratory committee for the United States presidential election of 2012.