Malone, S, Hughes, B, Roe, M, Mangan, S, and Collins, K. Factors that influence session-rating of perceived exertion in elite Gaelic football. J Strength Cond Res 34(4): 1176–1183, 2020—The current investigation examined the relationships between external training load (TL) measures and the session rating of perceived exertion (s-RPE) within Gaelic football players. Furthermore, we examined the effect that player experience, playing position, and 1-km time trial (TT) performance had on perception of TL. Physical performance (total distance, high-speed distance, very high–speed distance, max velocity, total accelerations, and maximal velocity exposures) and perceived TL (s-RPE) data were collected from 45 elite intercounty Gaelic football players (mean ± SD age of 24.2 ± 2.9 years; height: 180 ± 7 cm; mass: 81 ± 7 kg) over a 1-year period this resulted in 4,095 individual training session data being collected. There were moderate to very large associations between s-RPE and distance measures. Post hoc analysis revealed that the 0–1-year group had a higher s-RPE TL than the 2–3-year (d = 0.84 ± 0.33, small), 4–6-year (d = 0.91 ± 0.30, small), and 7+ year (d = 0.81 ± 0.30, small) groups. Midfielders reported higher s-RPE when compared with all positions (d = 1.21 ± 0.21, moderate). Half-backs (d = 0.81 ± 0.30, small), and half-forwards (d = 0.84 ± 0.31, small) had a higher s-RPE TL than the full-backs and full-forwards when external TL was accounted for (d = 1.21 ± 0.58, moderate). When aerobic fitness was considered, a 1.2% AU increase in s-RPE TL per 1 second increase in TT time (90% confidence limits: 1.07–2.64) when external TL was held constant was observed. The current investigation has shown moderate to very large associations between s-RPE and distance measures. When experience and fitness were considered as potential moderators of TL, it was observed that a given external TL may result in different internal responses between athletes. This potentially leaves individuals at risk of overtraining or failing to elicit positive adaptation. It is therefore vital that coaches and trainers give consideration to these mediators of s-RPE TL.