This paper presents a model for the prediction of the apparent fracture toughness of ferritic–pearlitic steels in notched conditions and operating at temperatures corresponding to their ductile-to-brittle transition zone. The model, here named the Notch-Master Curve, is based on the combination of the Master Curve of the material in cracked conditions and the notch corrections provided by the Theory of Critical Distances. In order to validate the model, the fracture resistance results obtained in 168 tests performed on CT specimens (84 for each material) are presented. These tests were carried out, for each material, in specimens with six different notch radii, from 0 mm up to 2.0 mm, and at three different temperatures within their corresponding ductile-to-brittle transition zone. It has been observed that the model provides good predictions of the fracture resistance in notched conditions for the two materials analysed.