Kenneth Wayne Jennings III (born May 23, 1974) is an American game show host and author who has hosted the syndicated quiz show Jeopardy! since 2021. He is best known for his success and streak as a contestant on the program: in 2004, he won 74 consecutive games, the longest streak in the show's history, and became the highest-earning American game show contestant up to that time. Before appearing on Jeopardy!, Jennings worked as a software engineer.
Afterward, Jennings pursued a career as an author, writing about his experience and exploring American trivia history and culture in a series of best-selling books. He also appeared on other game shows, including The Chase (where he was nicknamed "The Professor"), and hosted the Omnibus podcast from 2017 to 2025. Jennings returned to Jeopardy! in 2020 as a producer, and later guest-hosted the program after the death of host Alex Trebek that year. Jennings split full-time hosting duties with Mayim Bialik from 2021 to 2023, when he was made the sole host.
Jennings holds numerous game show records. As of 2025, he is the second-highest-earning American game show contestant, having won money on five different programs, including $4,522,700 on Jeopardy!. His original appearance on the program marks the longest winning streak on the show, netting him $2,522,700 over the course of his 75-day run. Despite his major success on Jeopardy!, Jennings does not hold the record for longest winning streak worldwide; that record is held by Ian Lygo, who won 75 games on the British game show 100% in 1998 (Jennings appeared on Jeopardy! for 75 days but won 74 games).
Jennings also holds the record for highest average correct responses per game and won the Jeopardy! The Greatest of All Time tournament. On July 30, 2025, he and Matt Damon became the second duo and the third celebrities overall to win the $1,000,000 top prize for their charity, Water.org, and the sixteenth overall million-dollar winners on Who Wants to Be a Millionaire. Jennings also won $100,000 on November 17, 2014.
Jennings was born in Edmonds, Washington, just outside Seattle. His father was an international lawyer and moved the family to South Korea when Ken was in first grade. His mother was a schoolteacher and worked for the Department of Defense in that capacity overseas. Jennings grew up viewing Jeopardy! on the American Forces Network. He lived in Korea and Singapore for 11 years and graduated from the Seoul Foreign School.
Upon returning to the United States, Jennings attended the University of Washington. He is a member of the Church of Jesus Christ of Latter-day Saints and spent two years as a volunteer missionary in Madrid, Spain. In 1996, Jennings transferred to Brigham Young University (BYU). One of his roommates was author Brandon Sanderson. Jennings also played on the school's quizbowl team, at one point serving as captain, and graduated in 2000 with a double major in English and computer science. After college, he lived in Salt Lake City and was a software engineer for CHG Healthcare Services, a healthcare placement firm in Holladay, Utah.
Before 2003, Jeopardy! contestants were limited to five consecutive wins. At the beginning of the show's 20th season in 2003, the rules were changed to allow contestants to remain on the show as long as they continued to win. After this rule change, and until Jennings's run, the record winning streak was set by Tom Walsh, who won $186,900 in eight games in January 2004. Jennings took the contestant exam for Jeopardy! in 2003, but did not hear back from the show for a year. He was given three weeks to prepare for his taping. Jennings prepared extensively by using a couch as a lectern and his young child's toy as a buzzer while his wife used flashcards and kept score.
Jennings's run began during Jeopardy!'s 20th season with the episode airing on June 2, 2004, in which he unseated two-time champion Jerry Harvey, and continued into season 21. In his first episode, the Final Jeopardy! answer was, "She's the first female track and field athlete to win medals in five different events at a single Olympics." Jennings responded, "Who is Jones?", using only the last name of Marion Jones (who was not stripped of her medals until 2007). Host Alex Trebek said, "We will accept that; in terms of female athletes, there aren't that many."
His streak underway, Jennings taped 48 episodes before his first one aired. His last program was taped on September 7, 2004, and aired on November 30, coinciding with the end of the November sweeps. Jennings lost his 75th game to challenger Nancy Zerg. Jennings responded incorrectly to both Double Jeopardy! Daily Doubles, causing him to lose a combined $10,200 ($5,400 and $4,800, respectively) and leaving him with $14,400 at the end of the round. As a result, for only the 10th time in 75 games, Jennings did not have an insurmountable lead going into Final Jeopardy!. Only Jennings and Zerg, who ended Double Jeopardy! with $10,000, were able to play Final Jeopardy!, as third-place contestant David Hankins failed to finish with a positive score at the end of the Double Jeopardy! round. The Final Jeopardy! category was Business & Industry and the clue was, "Most of this firm's 70,000 seasonal white-collar employees work only four months a year." Jennings appeared perplexed during the time allowed to write a response, while Zerg finished her response quickly. Zerg responded correctly with "What is H&R Block?" and wagered $4,401 of her $10,000, giving her a $1 lead over Jennings with his response still to be revealed. Jennings responded, "What is FedEx?", losing with a final score of $8,799 after his $5,601 wager was deducted. After his response was revealed, the audience gasped and Zerg appeared shocked to have won. Jennings was awarded $2,000 for his second-place finish, giving him a total of $2,522,700 for his Jeopardy! run. Zerg, whom Jennings called a "formidable opponent", finished in third place on the next show. The audience gave both contestants a standing ovation and Trebek called Zerg a "giant killer" as Jennings embraced her. According to the Associated Press, rumors of Jennings's defeat began circulating shortly after the episode was taped, and footage had leaked online by November 29.
Overall, Jennings gave over 2,700 correct responses on the program. His run was interrupted by the off-season break (July to September), 2004 Kids' Week, the Tournament of Champions (September 20 to October 1), the 2004 United States presidential election (November 2, when no first-run episode was scheduled; the remaining episodes of the week aired from Wednesday to Saturday), and the College Championship (November 10 to 23). As a result, Jennings went five months without a loss. He did not participate in the Tournament of Champions, as invitations are extended to only those champions (four wins or more) who have been defeated, with the exception of the winner(s) of the College Championship. On December 1, the day after his defeat, Jennings made a guest appearance at the start of the broadcast, during which Trebek acknowledged his success and enumerated the various game show records he had broken.
Jennings's 75 episodes were broadcast over 182 calendar days, and his run brought significant media attention and television ratings. According to the Nielsen TV National People Meter, Jeopardy!'s ratings were 22% higher during Jennings's run than during the same period in 2003. For several weeks of the streak, Jeopardy! was TV's highest-rated syndicated program, with ratings 30% higher than before Jennings's appearance. By the end of Jeopardy!'s 20th season several weeks later, the show had surpassed sister program Wheel of Fortune in the ratings, though Wheel still benefited from the streak in markets where Jeopardy! is its lead-in in the common scheduling tactic for both shows. Jennings was credited with boosting the program's popularity as a whole, which at that point had been on the air for two decades but primarily attracted an older demographic.