College campus tobacco-free policies are an emerging trend. Between September 2013 and May 2014, we surveyed 1309 college students at 8 public 4-year institutions across California with a range of policies (smoke-free indoors only, designated outdoor smoking areas, smoke-free, and tobacco-free). Stronger policies were associated with fewer students reporting exposure to secondhand smoke or seeing someone smoke on campus. On tobacco-free college campuses, fewer students smoked and reported intention to smoke on campus. Strong majorities of students supported outdoor smoking restrictions across all policy types. Comprehensive tobacco-free policies are effective in reducing exposure to smoking and intention to smoke on campus.