<p>A ship’s hull inherently contains initial imperfections that develop pitting corrosion over time, particularly in steel vessels. These factors directly affect and reduce the ultimate strength capacity of the ship. This study investigates the combined effects of these damage factors on the hull girder ultimate strength of double-hull oil tankers. In addition, the study investigates the residual ultimate bending strength of double-hull oil tankers under hogging and sagging conditions through a stress distribution method incorporating several modifications. Using the selected method, different levels of initial imperfections (including slight, average, and severe levels), and corrosion volume losses (ranging from 0% to 30%) are considered to represent the damage scenario. The analysis shows that the effect of initial imperfections on the residual ultimate bending strength under extreme load was negligible (approximately 8.5% at the severe level); however, when interacting with the pitting corrosion, significant reductions of up to 37.17% and 38.50% were observed in the average cases of hogging and sagging conditions, respectively. Further evaluation of the safety factors associated with the ultimate bending moment highlights the necessity of improved structural evaluation and maintenance to ensure operational dependability and safety.</p>