In mammals, the final maturation and transport of gametes, fertilization and early embryo development take place in the oviducts. Bisphenol S (BPS) is a substitute for bisphenol A in plastic manufacturing and, as a potential endocrine disruptor, may alter the oviduct physiology. Furthermore, bisphenols are fat-soluble and can accumulate in fatty tissues. The objective of this study was to assess the effect of a daily dietary exposure to BPS combined with a contrasted diet on the oviduct fluid (OF) proteome using an ovine model. Eighty adult cyclic ewes were allotted to four groups (20/group): over-fed consuming in their diet 50 µg/kg/day of BPS, under-fed consuming 50 µg/kg/day of BPS, and non-exposed controls in each diet group. After three months, the mean body condition score and plasma levels of glucose and non-esterified fatty acids were significantly higher in over- than in under-fed females. The proteins in collected OF samples (50 µg) were analyzed by nanoliquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS). Overall, 1563 proteins were identified, among which 848 were quantified. Principal component analysis of data revealed a clear discrimination of samples according to the diet and a segregation between BPS-exposed and non-exposed females in over-fed ewes. Hierarchical clustering of differentially abundant proteins (DAPs) identified two clusters of 101 and 78 DAPs according to the diet. Pairwise comparisons between groups revealed a stronger effect of BPS in over- than in under-fed females (70 vs. 24 DAPs) and a stronger effect of the diet in BPS-exposed than non-exposed females (56 vs. 36 DAPs). Functional analysis of DAPs showed an enrichment in metabolic processes, immune system, cell response to stress, and reproductive processes. This work highlights for the first time the important impact of BPS on the oviduct proteome with bigger effects in over- than underweight females.