Shade is defined as the coolness and darkness caused by shelter from solar radiation. In freshwater, shade is most commonly provided by riparian vegetation, which can affect water quality through its effects on temperature and light. The purpose of this research was to explore riparian shade influences on (1) fish distribution along reservoir littorals and (2) diel water quality patterns. Sampling was conducted in shaded and non-shaded paired sites in Columbus Lake, Mississippi, U.S.A. Differences in species distribution revealed that, in general, clupeids and most centrarchids were better represented in unshaded sites, while percids were better represented in shaded sites. Diel cycles of water quality variables were measured in situ over 24-h periods with auto-samplers and assessed using trigonometric polynomial regression to describe daily cycles. Analysis of covariance revealed all water quality variables differed between sites and most also varied between shaded and unshaded sites and exhibited daily cycles.