Assessing the intensity of college football rivalries is an annual exercise of sports columnists. Fan polling, average ticket price, and even the bad behaviors of athletes have been used to quantify and rank rivalries. For economists, market prices of tickets have an appealing behavioral interpretation as they represent fans’ marginal willingness to substitute game attendance for other sources of utility. We have collected secondary market data on 278,117 individual ticket sales at different points in the season for 171 home games played by Southeastern Conference (SEC) member football teams over a 2-year period. Our rich data set allows us to control for the quality of the seats and the effects of on-field successes or failures during the season. Since we use data from 2 successive years, we are also able to normalize the level effect on prices of certain stadiums. We construct a willingness-to-pay measure of fan interest in various matchups and use this to compare the intensity of different rivalries for SEC schools.