Hills, SP, Rogerson, DJ. Associatons between self-reported well-being and neuromuscular performance during a professional rugby union season. J Strength Cond Res 32(9): 2498–2509, 2018—Self-reported wellness is often used to monitor fatigue responses to training and competition. Constraints within team sports mean short-form wellness questionnaires are typically preferred to literature-validated documents. This research aimed to assess the relationship between self-reported wellness and neuromuscular (NM) performance during a professional rugby union season, and to identify changes in these parameters over a 12-week period. On the first training day each week, before activity, 37 players rated 5 wellness subscales (“fatigue/vigor,” “upper-body soreness,” “lower-body soreness,” “mood,” and “sleep quality/duration”) on a 1–5 Likert scale (1 representing the lowest wellness), and 5-repetition countermovement jumps (CMJs) were completed after a warm-up. Each week, total wellness, wellness subscales, and 4 CMJ measures for each participant were calculated as change from baseline. Within-participant correlations were determined between changes in wellness and CMJ measures, whereas week-to week differences and differences from baseline were assessed using Wilcoxon signed-rank tests. Within-participant correlations were compared for players grouped by age and position. Wellness and CMJ scores fluctuated according to physical stress, persisted beneath baseline throughout, and showed declining trends over 12 weeks. Very large (r = 0.7–0.89)/large (r = 0.5–0.69) correlations were identified between wellness and CMJ variables (positive: velocity, dip, time; negative: duration), and each wellness subscale displayed large/very large positive correlations with CMJ velocity. This was true for all subgroups, although subtle differences existed between ages and positions. It was concluded that players' subjective wellness is a useful tool, ideally used within a broader monitoring scheme, for monitoring ongoing NM fatigue, which increased from week to week.