Reduced reproductive efficiency in Local Iraqi roosters is one of the primary challenges facing local poultry breeding flocks. This decline can be attributed to several factors, most notably nutritional imbalances and suboptimal management, alongside the deterioration of physiological and reproductive performance, the present study aimed to investigate the effects of selenium—a trace element known for its broad physiological impact—and evaluate its efficacy as a dietary supplement on the semen quality parameters of roosters. A total of 80 roosters, 22 weeks of age, were utilized in this study. The birds were randomly assigned to four treatment groups (20 roosters per treatment), with two replicates per treatment (10 roosters per replicate), The roosters were fed a nutritionally balanced basal diet supplemented with selenium from the onset of the study, All birds underwent continuous training for semen collection to ensure acclimatization to the procedure, Semen was collected bi-weekly throughout the 3-month experimental period, and mean values for each trait were calculated monthly for data presentation, The study evaluated various seminal characteristics, including ejaculate volume, mass activity, individual sperm motility, sperm concentration, packed sperm volume (PSV), and the percentages of dead and abnormal spermatozoa. The results of the current study indicated that selenium supplementation exerted effects ranging from significant to highly significant (P < 0.05and P < 0.01) across all studied traits throughout the experimental period. These findings suggest that selenium serves as a safe and effective nutritional tool for enhancing the reproductive efficiency of roosters, thereby opening new horizons for future research into utilizing the semen of these roosters for experimental insemination and fertility efficiency testing.