Water velocities were measured at discrete cross-sections along an approximately 1-mile reach of the Kentucky Dam tailwater on September 12 and 17-18, 2020, using a 1200 kHz acoustic Doppler current profiler (ADCP). The data were geo-referenced with an integrated global navigation satellite system (GNSS) smart antenna with submeter accuracy. The ADCP and GNSS antenna were mounted on a marine survey vessel, and data were collected as the survey vessel traversed the tailwater along planned survey lines. There was typically one reciprocal pair (two passes) of data collected per line. There was a total of 53 survey lines equally spaced 100 feet apart and oriented approximately perpendicular to the primary flow direction. Data collection software integrated and stored the velocity and position data from the ADCP and GNSS antenna in real time. Data were processed using the Velocity Mapping Toolbox (Parsons and others, 2013) to derive temporally- and spatially-averaged water velocity values. These velocity measurements were collected during three different steady discharge conditions from the hydropower turbines at Kentucky Dam. The average rated discharges on September 12, 17, and 18 were 8,300 cubic feet per second (cfs), 59,000 cfs, and 28,000 cfs, respectively. These data were collected to understand flow patterns in the Kentucky Dam tailwater during different discharge conditions from the hydropower turbines at Kentucky Dam and may be used to assist in invasive carp capture and control programs.