Peak oxygen uptake (VO2peak) 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 VO2peak. In this study, the validity of a treadmill-based PRET to predict VO2peak 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 VO2 from the PRET to RPE endpoints 19 and 20 and age-predicted HRmax were compared with measured VO2peak. The VO2 extrapolated to both RPE19 and 20 over-predicted VO2peak (p < .001). However, extrapolating VO2 to age-predicted HRmax accurately predicted VO2peak (r = .84). Results indicate older adults can use a PRET to predict VO2peak by extrapolating VO2 from submaximal intensities to an age-predicted HRmax.