It is well-known that a single tensile overload, during the fatigue crack growth under constant loading amplitude, can induce the delay phenomenon. One of the basic mechanisms for fatigue crack growth in ductile metals is based on the crack-tip blunting under tensile loads. In this article, we investigate the fatigue crack growth delay behavior due to the single overload in the case of 12NC6 steel through compact tension specimens. An analytical method based on properly modified eN concepts is presented to predict the delay lives. The combination knowledge of the short cracks and the 3D constraint effect is important for the analysis in the vicinity of the blunt crack tip after overload. The present approach provides an analytical means to quantify the crack delay cycles in fatigue following a single tensile overload. The experimental results are in good agreement with the analytical modeling for different overload distributions.