Peak oxygen uptake (V̇O2peak) is reliably predicted in young and middle-aged adults using a submaximal perceptually-regulated exercise test (PRET). It is unknown whether older adults can use a PRET to accurately predict V̇O2peak. In this study, the validity of a treadmill-based PRET to predict V̇O2peak was assessed in 24 participants (65.2 ± 3.9 years, 11 males). The PRET required a change in speed or incline corresponding to ratings of perceived exertion (RPE) 9, 11, 13, and 15. Extrapolation of submaximal V̇O2 from the PRET to RPE endpoints 19 and 20 and age-predicted HRmax were compared with measured V̇O2peak. The V̇O2 extrapolated to both RPE19 and 20 over-predicted V̇O2peak (p < .001). However, extrapolating V̇O2 to age-predicted HRmax accurately predicted V̇O2peak (r = .84). Results indicate older adults can use a PRET to predict V̇O2peak by extrapolating V̇O2 from submaximal intensities to an age-predicted HRmax.