Notch and size effects generally show great influence on the fatigue behavior of engineering structures, which plays a vital role during their structural integrity and reliability evaluations. In this study, the influence of notch size effect on fatigue life and critical distance values were investigated. Particularly, a novel method for fatigue life distribution assessment of notched specimens was proposed based on Weibull model and critical distance theory. Experimental data of Al 2024-T351 smooth plate specimens and center hole plate (CHP) specimens with four different notch radii were utilized for model validation and comparison. Results show that all predicted lives of Al 2024-T351 CHP specimens are within the ±2 life scatter bands of experimental ones. Display omitted •Weibull model describes well the dispersity of fatigue lives of Al 2024-T351 alloys.•Influence of notch size effect on critical distance and fatigue strength were characterized.•Proposed model by coupling Weibull with critical distance theories for considering notch size effect.•Proposed model predictions of Al 2024-T351 center hole plate specimens are within ±2 life scatter bands of experimental ones.