The study presents a reliability-based fatigue life prediction model for the ocean current turbine rotor blades. Using the short-term distribution of the bending moment ranges, the 2-parameter Weibull distribution is used to fit the bending moment range data to obtain the long-term distribution. The long-term distribution is used to determine the number of load cycles for any given bending moment range. The published laboratory test data in the form of the ε-N curve is used in conjunction with the long-term distribution of the bending moment ranges in the prediction of the fatigue failure of the rotor blade using Miner’s rule. Future work on the reliability analyses and partial safety factors are included in the paper.