The purpose of this study was to examine the test-retest reliability and minimal detectable change (MDC95) of the hexagon test. The hexagon test is a routinely used measure of agility in the sports and rehabilitation professions, yet its reliability has not been investigated in prior research. A total of 26 college-aged men (n = 17) and women (n = 9) of various activity levels were recruited to participate in 3 testing sessions: baseline, 1 hour after baseline, and 48 hours after baseline. The results of this study indicated excellent test-retest reliability for both same-day intraclass correlation coefficient (ICC) model 3,1 = 0.938 and between-day ICC (3,1) = 0.924 analyses. The MDC95 for the hexagon test was 1.015 seconds. A significant difference in the mean times was identified during the same-day test-retest sessions (p < 0.001) but not the between-day test-retest sessions (p = 0.18). The significant differences identified between the baseline and the same-day retest session suggests a learning effect. The hexagon test shows excellent reliability for measuring agility, which supports its use as a tool to assess athletic performance and lower-extremity agility. Evidence of reliability, in addition to its ease of administration, makes the hexagon test a practical and effective method to measure agility. When using this test as a measure of agility, a change of greater than 1.015 seconds is necessary to be 95% certain that the change in time reflects improvement and exceeds measurement error. A practice trial is recommended prior to recording scores to attenuate the possibility of a learning effect.