We document the discovery of the mimic shiner, Notropis volucellus (Cope), in the Connecticut portion of the Connecticut River drainage. Mimic shiner can be distinguished from similar northeastern minnows in the field by the combination of a uniform silvery color, large eye, nearly terminal mouth, and a distinctive line of black pigment beginning at the anus and extending posteriorly almost to the base of the caudal fin. Further distinguishing features can be seen in the laboratory including elevated anterior lateral line scales and densely packed neuromasts on the top of the head. We suspect that mimic shiner is more widely distributed in the northeast than has been reported.