The data used in the manuscript "Implications of Biofouling on Cross-flow Turbine Performance", by Carl Stringer and Brian Polagye, are included in the files 'Large-Low.mat', 'Large-Med.mat', 'Large-High.mat', 'MED-MED.mat', 'MED-HIGH.mat', 'SMALL-MED.mat', 'SMALL-HIGH.mat', 'Clean.mat' '2019a.mat,' and '2019b.mat.' These files correspond to the different cases of turbine fouling discussed in the manuscript, respectively. The file naming convention is the size of the barnacles followed by level of density. Each turbine data file includes the structured arrays 'ts' (time-series) and 'stats' (statistics). 'ts' contains the time series of the recorded data for each 60s acquisition window. 'stats' contains the mean values for each 60s acquisition window.Variables included in each structured array are as follows: Uinf = free-stream velocity [m/s] FX = thrust force on the turbine [N] MZ = hydrodynamic torque on the turbine [N-m] turbVel = angular velocity of turbine [rad/s] turbPos = angular position of turbine [rad]