Although there is evidence on the predictors of adverse health outcomes in older individuals, walking speed has typically been measured in laboratory settings (LWS); LWS may be distinct from individuals' actual walking speed in their daily lives (DWS). We examined whether DWS differs from LWS among older adults, and its association with physical frailty. Participants were 90 community-dwelling older adults. A five-meter normal (LWS nor ) and maximum (LWS max ) walking speed was measured with a stopwatch. DWS was measured using a global positioning system-related smartphone application for one month during their daily lives. DWS avr , DWS max , and DWS sd were defined as the average, maximum, and standard deviation of walking speed for one month. Participants' mean DWS avr and DWS max were 1.28 m/s and 2.14 m/s, respectively, significantly slower than the mean LWS nor (1.42 m/s) and LWS max (2.24 m/s); the intraclass correlation coefficient between DWS and LWS were 0.188 to 0.341. DWS was significantly correlated with grip strength, one-legged stance, and LWS. The area under the receiver operating characteristic curve of DWS sd concerning pre-frailty was largest among DWSs, at 0.615, while that of LWS nor was 0.643. The findings suggest that DWS differs from LWS and is associated with physical function and pre-frailty.