Corn silk (CS) (Stigma maydis) has been used for centuries in traditional medicine (TM) worldwide to treat various disorders owing to its antioxidant, antidiabetic, diuretic, antimicrobial, and anti-inflammatory properties. The health benefits mentioned in traditional medicine and reliable sources originate from the chemical makeup of corn silk, which includes total phenols, polysaccharides, protein, fiber, alkaloids, minerals, and vitamins. Large quantities of CS, a major by-product of corn processing, are often discarded, dissipating valuable bio-resources. By utilizing CS to develop functional and health-promoting value-added products, a part of agricultural waste would be redirected toward zero-waste production while conserving the environment and increasing the agro-economy. Our present study focused on investigating the bioactive compounds and antioxidant capacities of CS from five corn genotypes harvested at three maturity stages, or three different days of sillking (DAS) in order to single out the most promising raw material that could be used to develop dietary supplements. The prevailing bioactive compounds were total phenols, which ranged from 2498.09 GAE/g (genotype ZP 6119k, 15 DAS) to 13580.62 GAE/g (genotype ZP 5550, 15 DAS). Assessment of antioxidant capacity using different methods will show which corn silk genotypes are most suitable for health development. The antioxidant capacities determined after ABTS⁺ scavenging activity ranged from 41.82 mmol Trolox/kg to 83.48 mmol Trolox/kg in CS extracts of two genotypes, ZP 6119k (15 DAS) and ZP 6263 (21 DAS), respectively. The results obtained in this study could be of exceptional importance for the maize breeding programs and selection of potentially most suitable hybrids for functional food and dietary supplement production.