The game had originally been schedule for Monday December 26, but when the AFL and NFL agreed to merge in 1970 and play a "world championship game" starting with the 1966 season the game was moved to January 1.
The Kansas City Chiefs finished the 1966 season with an 11–2–1 record, finishing first place in the Western Division. Len Dawson finished the season with 2527 passing yards and 26 touchdowns, with only 10 interceptions, giving him a 101.7 passer rating. The team's top wide receiver was Otis Taylor who caught 58 passes for 1297 yards and 8 touchdowns; Chris Burford also contributed by catching 58 passes for 758 yards and 8 touchdowns. Mike Garrett was the team's leading rusher, gaining 801 yards and 6 touchdowns. Other reliable options included Curtis McClinton (540 yards, 4 touchdowns) and Bert Coan (521 yards, 7 touchdowns). The Chiefs' offense consisted of five All-Stars: Len Dawson, Curtis McClinton, Otis Taylor, Jim Tyrer, and Ed Budde.
The Bills went into the 1966 AFL Championship having already won the game the previous two years. Though the game was to be played in Buffalo, the visiting Kansas City Chiefs were three-point favorites, mainly because of their explosive and innovative offense led by Head Coach Hank Stram. The Bills were a more conventional team with a solid defensive line and a running mindset on offense.
A Bills fumble on the opening kickoff gave the Chiefs a short field to work with, and Quarterback Len Dawson immediately took advantage of it, hitting Fred Arbanas for the game's first score. Jack Kemp's first pass for the Bills was a 69 yard score to Elbert Dubenion. Late in the second quarter and trailing 14–7, Kemp led the Bills to the Kansas City 10. Bobby Crockett was open in the endzone, but Kemp's pass was intercepted by Johnny Robinson, who returned the ball 72-yards, setting up a Mike Mercer field goal to close out the first half.
Buffalo found no offensive rhythm in the second half, and the Chiefs closed the game out in the fourth quarter with Dawson found Chris Burford for a 45 yard gain, setting up a one foot touchdown run by rookie Mike Garrett. Garrett scored his second touchdown less than two minutes later following another Bills fumble, sending the Chiefs to the AFL-NFL Championship Game.
1 – From 1966 to 1969, the first four Super Bowls were "World Championship" games played between two independent professional football leagues, AFL and NFL, and when the league merged in 1970 the Super Bowl became the NFL Championship Game.
2 – Dates in the list denote the season, not the calendar year in which the championship game was played. For instance, Super Bowl XLI was played in 2007, but was the championship for the 2006 season.