Moringa oleifera leaves (MOL), a superfood rich in protein and vitamins, is native to the Indian subcontinent. Moringa were added to the broodstock trout diet to examine their influence on the reproductive performance of male broodstock rainbow trout (Oncorhynchus mykiss). Females were fed with a commercial broodstock trout diet without any inclusion of moringa leaves. In 12 circular fiberglass tanks, 36 male rainbow trout aged 3+ (1786.36 ± 35.36 g; 56.08 ± 0.94 cm) were divided into four groups (n = 9) (control, MOL-1, MOL-2, and MOL-3) with three parallels each. Fourteen weeks of feeding trials were performed where powdered moringa leaf was used in the diets at various levels: 0% (control), 4% (MOL-1), 8% (MOL-2), and 16% (MOL-3). Sperm quality parameters and fertilization success were investigated. Sperm motility parameters were examined at 10.5 °C using a computer-aided sperm analysis (CASA) system, and all samples were analyzed on the same day. Sperm volume and seminal plasma osmolality did not differ significantly across groups (p > 0.05). Spermatozoa concentration (6.71 ± 0.25, 7.54 ± 0.31, 8.44 ± 0.55, and 7.66 ± 0.35 × 109 cells ml−1 in control, MOL-1, MOL-2, and MOL-3 groups, respectively), spermatocrit ratio (18 ± 2.55%, 25 ± 3.16%, 38 ± 6.44%, and 28 ± 5.15%), and motility duration differed significantly (p < 0.05) among groups. Total motility percentage did not change, but progressive motility (74.72 ± 5.94%, 88.52 ± 4.35%, 89.36 ± 1.76%, and 90.47 ± 2.67%) was considerably higher in all three moringa groups than in control one (p < 0.05). Average Path Velocity (VAP), Straight Line Velocity (VSL), and Curvilinear Velocity (VCL) significantly differ between control and treatment groups (p < 0.05). The fertilization rate in the MOL-2 group was similar to the control and MOL-3 groups, while significant differences were observed from the eyeing stage, with the highest result observed in the MOL-2 group (p < 0.05). Hatching rates were also highest in the MOL-2 group (81.65 ± 0.49%), followed by MOL-3 (79.08 ± 1.27%) and MOL-1 (74.40 ± 2.32%), with the control group having the lowest hatching rate (74.24 ± 0.98%) (p < 0.05). Progressive motility, VAP, VSL, and VCL have significantly enhanced in the moringa-treated groups than the control one, hence boosting the fertilization success. The present study revealed that moringa leaves in the diet improve the sperm quality parameters and enhance the reproductive performance in broodstock male rainbow trout (Oncorhynchus mykiss). Therefore, 8% moringa leaf can be recommended as a supplement diet for male rainbow trout broodstock.