Antimicrobial resistance (AMR) is an escalating global health crisis, causing an estimated 1.27 million deaths in 2019 and projected to reach 10 million annually by 2050, with an associated economic burden of up to US$100 trillion. Pseudomonas aeruginosa, a WHO-designated critical-priority pathogen, is a major cause of hospital-acquired infections and chronic respiratory disease in cystic fibrosis (CF). NAD(P)H quinone oxidoreductases (NQOs) are flavoenzymes that catalyse the reduction of quinones to their reduced form thus preventing reactive oxygen species (ROS) accumulation and oxidative stress. Given that many bactericidal antibiotics generate ROS as part of their killing mechanism, NQOs are proposed to modulate antibiotic susceptibility through redox regulation. Clean NQO knock-out strains were constructed via suicide plasmid mutagenesis, verified by sequencing, and complemented using Gateway cloning. Antimicrobial susceptibility testing (AST) across multiple antibiotic classes was conducted using microbroth and agar dilution, disk diffusion, and minimum bactericidal concentration assays, alongside phenotypic analyses of motility, growth, and cell morphology. The NQO knock-outs showed increased susceptibility to fluoroquinolones and distinct resistance profiles across aminoglycosides, with altered responses to other antibiotic classes. Knock-outs also exhibited differences in swimming and swarming motility, as well as altered growth rates compared to the wild type. Preliminary evidence suggests these changes reflect disrupted redox balance and impaired oxidative stress management. Ongoing work will assess biofilm formation, siderophore production, and other antibiotic resistance-associated phenotypes alongside ROS generation using flow cytometry and fluorescence microscopy to define how NQOs influence redox homeostasis and antibiotic resistance in P. aeruginosa.