PFAS chemicals are ubiquitous in the global environment due to their widespread use in consumer and industrial products and thus form an emerging risk factor for male reproductive health. In recognition that male reproductive health and overall health are inextricably linked, we explored the effects of PFAS exposure on basic sperm parameters using a mouse model featuring in vitro sperm exposure protocols and a 3-month in vivo exposure regimen. To assess the direct impact of PFAS, cauda epididymal spermatozoa were exposed to a cocktail of nine PFAS chemicals formulated to mimic that of environmental samples (low-dose) as well as an additional cocktail featuring a ten-fold elevation in the concentration of each PFAS (high-dose). Among the suite of functional endpoints assessed, we recorded a significant reduction in progressive motility and straightness immediately after resuspension of sperm in the high-dose PFAS cocktail (p<0.05, n=3); a response that was accompanied by a subsequent reduction in straight line velocity at 1 h (p<0.05). Spermatozoa exposed to a low dose of PFAS for 1 h demonstrated a reduction in the straight-line distance they travelled (p<0.01). In assessing the impact of in vivo PFAS exposure, we recorded a reduction in the rate of daily sperm production (p=0.0192, n=8), as well as pronounced changes in the miRNA profile of mature spermatozoa. Specifically, among 2057 identified miRNAs, 137 (7.6%) were significantly increased in the sperm of PFAS treated mice, whereas 56 (2.7%) were suppressed (+/- 1.5-fold, p<0.05 in comparison to controls). The differentially regulated miRNAs included several previously linked with organismal injury and abnormalities (e.g. miR-130b-5p, miR-150-3p and miR-190a-5p), reproductive system disease (miR-130b-5p and miR-190a-5p), cell death and survival (miR-486-5p) and cellular development (miR-130b-5p, miR-486-5p and miR-574-3p). This study presents new evidence that PFAS chemicals impact sperm quality and begins to elucidate the mechanisms generating that impact.