The study examined the associations between eHealth literacy (eHL) and 24-hour exercise behavior in 553 older Chinese adults aged 60–74 years. Higher eHL was associated with greater light physical activity (LPA, b=0.40, p<0.001), moderate-to-vigorous physical activity (MVPA, b=0.19, p<0.001) and lower sedentary behavior (SB, b=-0.43, p<0.001) after adjustment for age, sex, and education. eHL was also positively associated with self-efficacy (b=0.47, p<0.001). Self-efficacy partially mediated these associations with small indirect effects for LPA [0.04, 95% CI (0.00, 0.09)], MVPA [0.08, 95% CI (0.03, 0.13)] and SB [−0.06, 95% CI nil 0]. Self-efficacy moderated the associations for LPA (F=76.82, p<0.001), SB (F=75.07, p<0.001), and sleep duration (F=4.74, p<0.001), but not for MVPA. The models explained 26% of the variance in LPA, 6% in MVPA and 30% in SB. The findings are cross-sectional and require confirmation in long-term studies.