Objectives: To systematically review the literature on the effects of ankle supports on lower extremity biomechanics during functional tasks. Design: Systematic review with meta-analysis. Methods: Eight electronic databases were searched from inception to July 2019. Studies of biomechanical outcomes during functional tasks that used a within-participant (repeated measures) design were included. Two independent reviewers screened studies, extracted data, assessed the methodological quality of the included studies and rated the quality of evidence. Meta-analysis was performed and reported as standardised mean differences and 95% confidence intervals. Results: A total of 8350 studies were identified in the electronic search and 42 studies involving a total of 761 participants were included in the review (21 studies included for qualitative reporting and 21 studies in the meta-analysis). Most individual studies and the meta-analyses demonstrated no effect of ankle supports on ground reaction force or ankle inversion angle. However, there was high quality evidence that ankle taping decreased plantarflexion angle at initial contact during landing from a height (P = 0.0009, standerdised mean differences = 0.72, 95% confidence intervals = 1.15, 0.03, I 2 = 3%). The effect of ankle supports on transverse plane ankle biomechanics has not been adequately investigated. Conclusions: Ankle taping only decreased plantarflexion angle at initial contact during landing from a jump. Ankle supports did not affect inversion angle or forces in linear and multiplanar tasks. There was insufficient evidence on the effect of ankle supports on ankle transverse plane biomechanics.