Macrochelys temminckii (Alligator Snapping Turtle) populations have experienced range-wide declines over the past century, and records of this species have become increasingly rare in the northern portion of its range. We report the first record of an Alligator Snapping Turtle in Illinois since 1984, only the second in the past 50 years. This individual was captured in a tributary of the undammed portion of the Mississippi River in close proximity to the last 3 published records in Illinois. It is possible that this region provides the last accessible, suitable habitat for this species in Illinois.