This study investigated the frailty change patterns among Korean older adults during 2006–2020 and the effect of activity limitations induced by the fear of falling (FOF) on these patterns. We employed a descriptive longitudinal design utilizing data from Waves 1 to 8 of the Korean Longitudinal Study of Aging. The exclusion criteria were a baseline age < 65 years, frailty index (FI) captured only at baseline, and death or unknown survival status. Multilevel modeling, combining regression equations at two levels, was used to examine the effect of activity limitations due to FOF on frailty, adjusting for other confounding factors. An increase in FI (1.97; p <.001) was demonstrated in participants who had experienced falls versus those who had not in the past 2 years. Notably, those facing activity limitations due to FOF exhibited a more significant increase in FI (4.62; p <.001) compared with those without; frailty progression intensified over time in the former (0.54, p <.001). Activity limitations due to FOF had a more pronounced impact on frailty than falls; moreover, these activity limitations accelerated the progression of frailty. Healthcare providers must prioritize addressing FOF by employing both physical and psychological interventions to mitigate activity limitations and ultimately decelerate frailty.