Season 23 (2006-2007)
- Both Jeopardy! and Wheel of Fortune abandon SDTV, and became the first syndicated game shows to air in HDTV.
- After this season, Merv Griffin died of prostate cancer on August 12, 2007, at the age of 82. KingWorld shuts down on August 20, 2007.
- This is the last season to air during Merv Griffin's lifetime.
- This is the last full season to be distributed by KingWorld, due to being replaced by CBS Television Distribution the next season.
- This season is both the last season to have the KingWorld "Star Shooter" logo, and the only season to have KingWorld's last logo.
- The opening credits have changed to a blue starry background, where many photographs are seen throughout before the Jeopardy! logo came into view. When Johnny said "This is Jeopardy!", the Jeopardy! logo came into view, and is set on a starry blue and orange background, with a grid pattern, with the Jeopardy! logo in blue. Finally, the Jeopardy! logo then zooms forward, in which the "A" reveals the 2002-2009 set.
- The gameplay round, and Daily Double title cards changed their color to a starry blue background with the text appearing in orange.
- The contestant intros and Final Jeopardy! winnings strip change its color to black with white borders and uses Franklin Gothic.
- The font for the video clues and the Final Jeopardy! segments were changed back to Optima.
- The position labels in the closing credits, as well as the copyright notice and the "Created by Merv Griffin" text, have their strips removed, and all credits from Harry Friedman's credit to Bob Sofia's credit have their font changed to Helvetica when Bob Sofia became an associate producer.
- Lisa Finneran, Rocky Schmidt, and Gary Johnson became supervising producers.
- Starting with this season, Johnny Gilbert was credited as the announcer in the closing credits.
- The set receives a few minor facelifts to accommodate the transition to HDTV:
- The trapezoid-shaped podiums were removed, so the contestant podiums were wider spaced apart, and the podiums became black colored squared with a sepia border.
- The game board is now consisted of a nearly seamless projection wall, giving the set a more HD-friendly atmosphere.
- Both sides on the game board consisted of 4 brown squares with a white marble border.
- Also, during the first two weeks of taping, the ring-in lights on the contestant lecterns are in red LED. But due to visibility issues, the contestant ring-in lights were changed back to white from the third week of this season until the end of this set's run.
- In the first full closing credit roll episode of the season, the split-screen background changed to a blue starfield with light blue bars, one on the top and one on the bottom, and the yellow bar in the middle, with the Sony Pictures Studios credit scrolling to an end on the center-right.
- On later full credit rolls of this season, the Sony Pictures Studios credit fades in at the center-right.
- The last KingWorld logo first appeared on the December 25, 2006 episode. In this version, the 1998-2006 "Star Shooter" logo was redesigned, with silver trim in the background, the logo was tilted, and the sky in the background changed from golden-brown to a cloudy blue and white.
- The last KingWorld logo did not appear until the December 25, 2006 episode, but it still used the jingle from the 1998-2006 logo.
- On later episodes of this season, starting on January 22, 2007, the intro was changed. There is a photograph of the Coliseum in Rome, and a photograph of the Eiffel Tower in Paris, France, the photographs of a tiger, and Stonehenge, respectively; the Kremlin photograph, and the photograph of a blue butterfly on a green leaf; the Great Wall of China, and the orangutan; and finally, the photograph of Albert Einstein.
- Starting this season and lasting until Season 35, the Rock & Roll Jeopardy! theme music is used in the introductions during the Teen Tournament, College Championship, and Kids Week.
- This is the first of the only two seasons to have two Teen Tournaments.
- Season 23 of Jeopardy! kicks off on September 11, 2006.
- On the September 22, 2006 episode, the real 5,000th episode aired on this date.
- On the September 25, 2006 episode, the red ring-in lights on the contestant lecterns changed their color to white as they were in the pre-high definition television version of the set due to visibility issues, particularly in standard definition television.
- On the October 2-6, 2006 episodes, Back to School Week was held for the last time.
- The Celebrity Jeopardy! tournament is taped at New York City's Radio City Music Hall and was aired from November 8-21, 2006.
- New travel podiums are introduced similar to the ones at home base except the lights are located on the score display and the Final Jeopardy! Monitors.
- On the March 16, 2007 episode, the first-ever three-way-tie occurs with the guys all winning $16,000 [Scott, Jamey, and Anders]. In fact, it was also the only nonzero three-way tie to date in history.
- On the March 19, 2007 episode, all three contestants come back and play again, which marked the only time in history to feature three returning co-champions.
- The College Championship was held at USC and aired from April 30-May 11, 2007.
- This was the first time, in which two contestants on one previous episode on the April 17, 2006 episode, but returned due to technical difficulties; Brian Lamb returned on the June 26, 2007 episode, and lost a game, and Holly Owens returned on the July 3, 2007 episode, and won two games.
- The Teen Tournament Summer Games air from July 16-July 27, 2007
- Season 23 of Jeopardy! wraps up on July 27, 2007.
- Summer reruns air from July 30-September 7, 2007 with replacement fee plugs. Reruns later air on weekends from 2007-2008. On most of those reruns, the CBS Television Distribution logo replaces the KingWorld logo.