The purpose of this study was to determine the relationship between Functional Movement Screen (FMS) score and the risk of time-loss injury in experienced male rugby union athletes. A secondary purpose was to determine the relationship between FMS-determined asymmetries and the risk of time-loss injury in these athletes. Functional Movement Screen scores were collected from male rugby union athletes (n = 73) during preseason and half-way through one 8-month season. Time-loss injury data were collected throughout the full season. A receiver-operator characteristic curve was created for each half of the season to identify FMS composite and asymmetry cut-off scores associated with increased likelihood of injury and determined odds ratios, sensitivity, and specificity in evaluating FMS as a predictor of injury risk. Odds ratio analyses revealed that when compared with those scoring >14, athletes with an FMS ≤14 were 10.42 times more likely (95% confidence interval [CI]: 1.28-84.75, p = 0.007) to have sustained injury in the first half of the season and 4.97 times (95% CI: 1.02-24.19, p = 0.029) more likely in the second half of the season. The presence of asymmetries was not associated with increased likelihood of injury. Experienced male rugby union athletes with FMS composite scores ≤14 are significantly more likely to sustain time-loss injury in a competitive season than those scoring >14. The quality of fundamental movement, as assessed by the FMS, is predictive of time-loss injury risk in experienced rugby union athletes and should be considered an important preseason assessment tool used by strength and conditioning and medical professionals in this sport with inherently high injury rates.