It is appropriate to wear casual attire to a football game. Anything from jeans and a tee to a sports logo sweatshirt is perfectly suitable. Represent the team of choice with clothing or accessories featuring the team colors or logo.
Many fans at football games coordinate clothing with their team of choice, so match clothing to the team logo or colors. Most stadiums have a fan shop with t-shirts, hats, sweatshirts and accessories for easy access. Football game attire is rarely dressy, so skip formal shoes or uncomfortable clothes.
For active fans planning on standing in the bleachers, wear comfortable tennis shoes and loose-fitting clothes. For outdoor games, bring extra layers and gloves.