300M steel has a unique combination of ultra high strength with high fracture toughness, which makes it an excellent candidate for aircraft landing gear applications. However, it is vulnerable to corrosion, corrosion fatigue and stress corrosion cracking damage. Therefore, it is important to find surface treatment methods to mitigate foreign object damage (FOD), corrosion fatigue damage and stress corrosion cracking. The benefits of applying low plasticity burnishing (LPB) to 300M steel on both the fatigue and corrosion fatigue performance was compared with the shot peened (SP) and low stress ground (LSG) conditions. LPB produced residual stress state resulting in a depth of compression of 1.27 mm (0.050 in.), while shot peening led to depth of compression of 0.127 mm (0.005 in.) LPB treatment dramatically improved both the HCF performance and corrosion fatigue strength. The S-N curve behavior for LSG with and without the presence of a simulated FOD (foreign object damage) showed a dramatic decrease in fatigue life from about 107 cycles at an Smax of 207 MPa (30 ksi), to 105 cycles at an Smax of 760 MPa(110 ksi) with no discernible endurance limit behavior under corrosion fatigue condition. The HCF behavior and corrosion fatigue behavior with a 0.5 mm (0.020 in.) deep notch was even worse. In contrast, LPB treated specimens with a 0.5 mm (0.020 in.) deep surface FOD showed a definite endurance limit of 1035 MPa (150 ksi) under corrosion fatigue conditions. Mechanistically, the effect of corrosion and FOD resulted in early crack initiation and growth, thus resulting in dramatic decrease in fatigue performance. Despite the existence of similar corrosion conditions, the deep compressive surface residual stresses from LPB treatment, helped to mitigate the individual and synergistic effects of corrosion fatigue and FOD.