As with all sports leagues, there are several significant rivalries between teams and notable players in the National Football League (NFL). Rivalries are occasionally created due to a particular event that causes bad blood between teams, players, coaches, or owners, but for the most part, they arise simply due to the frequency with which some teams play each other and sometimes exist for geographic reasons.
Rivalries in the NFL are commonly recognized as such by fans and players alike. While many rivalries are well established, others are of more recent vintage, accepted as existing by the nature of the competition and history between the two teams. Other rivalries have fallen by the wayside due to league realignment and a reduction in frequency of meetings. Many modern rivalries are formed simply due to the two teams being within the same division.