足球阵式是在足球比赛中球队如何将球员布署在球场上。阵式上大致可分为攻击阵式或防守阵式。形容阵式的方法由后卫开始计算至前线，但不把守门员计算在内。例如，4-4-2阵式是指有四个后卫、四个中场及两名前锋，通常以三至五个数字来形容阵式。无论职业或业余均有各自足球阵式，只是排阵的严谨程度不同。

在阵式上配合战术运用，例如使用4-4-2阵式，可以主攻、防守或平排去排阵。

阵式是可以在比赛进行时改变，但需要球会适应阵式的改变的位置。球队改变阵式的原因大致是改变攻击或防守模式，或有球员被逐离场后，进行补位工作。部份阵式是动态，球会可在转换前或后的位置，例如4-2-4阵式可转换为2-4-4阵式。

In association football, the formation describes how the players in a team are positioned on the pitch. Different formations can be used depending on whether a team wishes to play more attacking or defensive football.

Formations are used in both professional and amateur football matches. In amateur matches, however, these tactics are sometimes adhered to less strictly due to the lesser significance of the occasion. Skill and discipline on the part of the players is also needed to implement a given formation effectively in professional football. Formations need to be chosen bearing in mind which players are available. Some of the formations below were created to address deficits or strengths in different types of players.