Prior to the season, the NFL club owners voted to increase the regular season roster limit from 37 to 40 active players, the largest in league history up to that point. This standard would remain in place until the 1974 season.
New uniform rules
The 1964 season introduced a noteworthy change in uniform rules. While the league had dictated since that the home team must wear a colored jersey and the visitors a white one, teams were now given the option of wearing their white jerseys at home. As a result, the Browns, Cardinals, Colts, Cowboys, Rams, Redskins, Steelers and Vikings did so, while the rest reverted to home colors the following year. The Cardinals would not wear red at home until 1966, the Rams would not do so again until 1972, the Browns only once until 1975, and the Cowboys, aside from an unwilling use of their blue tops as the "home" team in Super Bowl V, have since continuously worn white at home. The Steelers would wear white at home for most home games from 1966 until 1969, but would not wear white as the "home" team until Super Bowl XL in 2005 and have not worn white in a game in Pittsburgh since Three Rivers Stadium opened in 1970.
Conference races
The Western Conference race started with Baltimore losing its opener at Minnesota, 34–24. After that, the Colts went on an 11-game winning streak, taking the lead on October 4 with their 35–20 win over the Rams, and clinching a spot in the title game on November 22. In the Eastern Conference, the Browns and the Cardinals played to a 33–33 tie on September 20, and were both 4–1–1 after six games. In Week Seven, Cleveland beat New York 42–20, while St. Louis fell to Dallas, 31–13. When the Cardinals beat the Browns 28–19 in Week Thirteen, they were only a game behind and needed a win and a Cleveland loss to have a chance for a playoff. St. Louis won, 36–34 in Philadelphia, but Cleveland also won, 52–20 over the Giants.
Week
Western
Eastern
1
4 teams
1–0–0
3 teams
1–0–0
2
Tie
1–0–1
Tie
1–0–1
3
Los Angeles Rams
2–0–1
Tie
2–0–1
4
Baltimore Colts
3–1–0
Tie
3–0–1
5
Baltimore Colts
4–1–0
Tie
3–1–1
6
Baltimore Colts
5–1–0
Tie
4–1–1
7
Baltimore Colts
6–1–0
Cleveland Browns
5–1–1
8
Baltimore Colts
7–1–0
Cleveland Browns
6–1–1
9
Baltimore Colts
8–1–0
Cleveland Browns
7–1–1
10
Baltimore Colts
9–1–0
Cleveland Browns
8–1–1
11
Baltimore Colts
10–1–0
Cleveland Browns
8–2–1
12
Baltimore Colts
11–1–0
Cleveland Browns
9–2–1
13
Baltimore Colts
11–2–0
Cleveland Browns
9–3–1
14
Baltimore Colts
12–2–0
Cleveland Browns
10–3–1
Final standings
W = Wins, L = Losses, T = Ties, PCT= Winning Percentage, PF= Points For, PA = Points Against Note: Prior to, the NFL did not include tie games when calculating a team's winning percentage in the official standings
The Playoff Bowl was between the conference runners-up, for third place in the league. This was its fifth year and it was played a week after the title game.
