The 1966 Denver Broncos season was the seventh season for the team in the American Football League (AFL). For the second straight season the Broncos posted a record of four wins, and ten losses, ranking last again for the fourth time in the AFL's Western Division. Following the second game of the season, head coach Mac Speedie abruptly resigned, and offensive line coach Ray Malavasi was the interim head coach for the remaining twelve games.
Denver's offense set a dubious all-time AFL record in 1966 with the fewest total points scored in a season, with 196, or 14 per game. The Broncos are the last team in major professional football (AFL or NFL) to go an entire game without picking up a first down, which they did in Week One at Houston.
This would be the final season that the "Bucking Bronco" logo would appear on the helmets.