Flathead catfish (Pylodictus olivaris) populations were sampled in three northeastern Mississippi reservoirs (Aberdeen, Columbus, and Aliceville) along the Tennessee-Tombigbee Waterway to evaluate stock characteristics. Specifically, data were collected on relative abundance, growth, mortality, recruitment, and size structure. These samples were part of a statewide effort to document current population status in reservoirs and to develop management goals. Sampling was conducted in late summer (July-August) during 2011-2013 using low-frequency electrofishing. All fish 250 mm total length and greater were aged using pectoral spine sections. Relative abundance (fish km-1) was higher in Aliceville Lake (12.56 fish km-1) than in Aberdeen Lake (7.54 fish km-1) or Columbus Lake (7.37 fish km-1), but length-frequency distributions, growth and annual mortality rates, and recruitment variation of flathead catfish were similar among reservoirs. This is in contrast to downstream gradients of fish population metrics typically observed in river ecosystems, which could be due to habitat homogenization resulting from navigation-related anthropogenic activities.