Current fatigue assessment of welded joints isbased on fatigue curves in which several effectsknown to influence the fatigue strength, such asthe weld geometry, residual stresses, and materialvariations are included. The present work aimsto investigate the influence of including the weldgeometry, as obtained by laser scanning, onuncertainty in fatigue assessment.The investigation involves 33 butt welds inS690 and 32 butt welds in S960, subjected tolow cycle fatigue. Laser scanning is conductedon each specimen to construct a finite elementmodel incorporating the actual weld geometry.Various fatigue indicators are explored to assesstheir effectiveness in reducing fatigue uncertainty,combined with a nonlocal model to accountfor the stress distribution. Using a Weibulldistribution based on the weakest-link theory, theperformance of the fatigue indicators in reducinguncertainty is evaluated.The highly stressed volume nonlocal modelwith maximum principal stress exhibited thelowest uncertainty, with scatter indices of 3.69 forS690 and 3.63 for S960, compared to higher valuesof 5.11 and 8.42 for the nominal stress approach,respectively. These findings demonstrate theinfluence of weld geometry on uncertainty infatigue assessment of butt welded joints.The study also reveals a relationship betweenthe local stress and weld toe radius, demonstrating an exponential stress-raising effect as the weldtoe radius decreases. However, the influence ofother geometric weld features on local stress couldnot be explicitly distinguished due to a lack ofclear correlation.