We assessed the potential public health benefit of the National Bus Pass, introduced in 2006, which permits free local bus travel for older adults (≥ 60 years) in England. We performed regression analyses with annual data from the 2005-2008 National Travel Survey. Models assessed associations between being a bus pass holder and active travel (walking, cycling, and use of public transport), use of buses, and walking 3 or more times per week. Having a free pass was significantly associated with greater active travel among both disadvantaged (adjusted odds ratio [AOR] = 4.06; 95% confidence interval [CI] = 3.35, 4.86; P < .001) and advantaged groups (AOR = 4.72; 95% CI = 3.99, 5.59; P < .001); greater bus use in both disadvantaged and advantaged groups (AOR = 7.03; 95% CI = 5.53, 8.94; P < .001 and AOR = 7.11; 95% CI = 5.65, 8.94; P < .001, respectively); and greater likelihood of walking more frequently in the whole cohort (AOR = 1.15; 95% CI = 1.07, 1.12; P < .001). Public subsidies enabling free bus travel for older persons may confer significant population health benefits through increased incidental physical activity.