•A modified generalized local model considering multiaxial stress and stress gradient is developed.•A novel probabilistic framework for notch fatigue analysis considering size effects is established.•Probabilistic fatigue life prediction of TA19 notched specimens with different scales are conducted. Structural integrity assessments with discontinuities are critical for ensuring operational life and reliability of engineering components. In this work, through combining with the generalized local model, a probabilistic framework is proposed for fatigue life assessment of notched components under size effects, in which the Smith–Watson–Topper damage parameter is utilized to characterize the multiaxial stress state at the notch tip. In particular, an effective stress concept is introduced to characterize the inhomogeneous stress distribution within the notch region. Finally, experimental data of TA19 notched specimens with different scales are utilized for model validation and comparison, results show that the proposed framework yields acceptable correlations of predicted fatigue lives with experimental ones. Display omitted