Of the many environmental factors that could affect swimming performance and critical swimming speed (U_crit), turbidity has received relatively little attention. The purpose of this study was to examine the effects of turbidity on Golden Shiner (Notemigonus crysoleucas) swimming performance through the analysis of critical swimming speed. It was found that turbidity had an effect on critical swimming speeds; critical swimming speeds increased significantly with rising turbidity values. At the highest turbidity levels reported in this paper, Golden Shiner experienced a 56.5% increase in critical swimming speed over controls swimming in clear water. We likewise observed an increase in swimming efficiency and cost of transport with increasing turbidity. We suggest that a hydrodynamic effect may be the most likely explanation for the increase in performance and swimming efficiency observed in this study.