Adults are encouraged to maintain levels of physical activity throughout their life span. This study describes gait performance and ambulatory activity (as a key component of physical activity) in 15 community- dwelling octogenarians and examines the association between activity measured continuously for 5 days with a tri-axial accelerometer and clinical measures of balance and functional mobility. Outcomes represented macro features of ambulatory activity and included volume, pattern and variability of activity. Micro gait outcomes were derived from each walking bout and represented 14 discrete spatio-temporal characteristics of gait. Participants walked a median of 9,294 steps/day (range 5,121-18,231). For macro outcomes, the strongest associations were established for Timed up and Go (TUG) single and dual task times and mean bout length (rs = -.66, p = 0.006, and -.68, p = 0.005 respectively; Spearman’s rho), and TUG dual task and accumulation of walking bouts (alpha) (α) (rs = -.67, p = 0.006). For micro outcomes, there was a positive correlation between step velocity and the Activities Balance and Confidence Scale (rs = .67 p = 0.006), and a negative correlation between step velocity and TUG single task (rs = .71, p = 0.003). TUG dual task showed a positive association with step time asymmetry (rs = .65 p = 0.008) and swing time asymmetry (r = .66, p = 0.004). For this group of active octogenarians, associations between ambulatory activity and functional mobility were stronger than for balance.