Background Higher physical activity (PA) and lower sedentary behaviour (SB) are associated with better muscle strength, balance, and functional ability, which are imperative for avoiding falls. This systematic review aimed to describe the association between objectively measured PA and SB with falls, fear of falling, and fractures. Methods Six databases were searched from inception to July 21, 2020 for articles reporting the association of objectively measured PA/SB with falls, fear of falling, and/or fractures in community-dwelling older adults ≥60 years old. Results were synthesized in effect-direction heat maps and albatross plots expressed as Pearson's correlation coefficients (R). Results A total of 43 articles were included, representing 27,629 (range 26–5545) community-dwelling older adults (mean [SD] age 76.6 [8.4] years, 47% female). Longitudinal associations were reported in 13 articles and cross-sectional associations in 30. Falls were reported in 11 articles, fear of falling in 18 and fractures in 2. Higher PA and lower SB were associated with less fear of falling (median [interquartile range] Rs = steps: -0.214 [0.249; -0.148], total PA: -0.240 [0.267; -0.144], and moderate-to-vigorous PA: -0.180 [0.382; -0.121]), but these associations did not extend to falls or fractures, which showed inconsistent effect directions. Conclusion Fear of falling is associated with less engagement in PA and more SB, thus indicating that it is a psychological barrier to an active lifestyle. Varying effect directions for associations between PA and SB with falls and fractures may provide evidence for non-linear associations and require further research considering details of the fall or fracture incident. PROSPERO registration number CRD42018103910