Despite having a higher risk of cardiovascular disease (CVD), there are currently limited data for stratifying CVD risk among cancer survivors. The purpose of this study was to uncover the relationship of subjective gait speed with incident CVD among cancer survivors.This retrospective observational cohort study analyzed data from the JMDC Claims Database between 2005 and 2021 including 56,589 patients with a prior history of breast, colorectal, or stomach cancer but no history of CVD. Gait speed was evaluated using information from self-reported questionnaires collected during health checkups. The primary endpoint was composite CVD outcome, which included heart failure, myocardial infarction, angina pectoris, and stroke.The median (interquartile range) age was 54 (48-61) years, and 20,981 (37.1%) were male. Among them, 25,933 patients (45.8%) reported fast gait speed. During a mean follow-up period of 1002 ± 803 days, 3,221 composite CVD outcomes were recorded. In multivariate Cox regression analysis, slow gait speed was associated with a higher risk of developing CVD compared with fast gait speed (hazard ratio, 1.14, 95% confidence interval, 1.06-1.22). This association was consistent across a variety of sensitivity analyses.We demonstrated that subjective slow gait speed was associated with a greater risk of CVD development among cancer survivors. This suggests the potential value of gait speed assessment for the CVD risk stratification of cancer patients as well as the clinical importance of maintaining exercise capacity among patients living with cancer.