Objectives were to (1) characterize the distribution and variability of serum anti-Müllerian hormone (AMH) concentration, (2) examine the association between serum AMH and reproductive outcomes, (3) estimate genomic heritability for serum AMH, and (4) identify putative single nucleotide polymorphisms associated with phenotypic variation in serum AMH in Irish dairy cows. Serum AMH (pg/mL) was determined from a single blood sample collected between 7 and 13 d after first insemination at detected estrus (IDE) in 2,628 dairy cows managed under pasture-based seasonal-calving system. Overall, serum AMH had a positively skewed distribution with the mean (±SEM), median, minimum and maximum concentrations of 326 ± 4, 268, 15 and 2,863 pg/mL, respectively. Cows were categorized into low (<150 pg/mL; n = 526, lowest 20%), intermediate (≥150 to ≤ 461 pg/mL; n = 1,576, intermediate 60%) and high serum AMH (>461 pg/mL; n = 526, highest 20%) groups and associations with reproductive outcomes were tested. Cows with high and intermediate serum AMH had 1.5 times greater odds of pregnancy within 84-d after mating start date compared with cows with low serum AMH (91 and 90 vs. 86%, respectively); however, pregnancy to first IDE and pregnancy rate within 21 and 42-d after mating start date did not differ between AMH categories. Serum AMH was moderately heritable (genomic heritability estimate of 0.40 ± 0.05), and 68 single nucleotide polymorphisms across Bos taurus autosomes 7 and 11 were associated with phenotypic variation in serum AMH. Serum AMH concentration had high variability and moderate heritability; however, a reduced fertility in the low serum AMH group was only evident at the end of the breeding season.