A quality by design (QbD)-based on high resolution, stability-indicating high performance liquid chromatography (HPLC) method was developed for determining the impurities in Linezolid oral suspension dosage forms. Using this method six known were impurities qualified, and two degradants were quantified with excellent peak resolution. Using pH 3.0 0.02M potassium phosphate buffer as buffer. For mobile phase-A consisted of 80% buffer, acetonitrile 10%, and 10% methanol in the ratio of 80:10:10(v/v/v), while mobile phase B consisted of methanol and buffer in the ratio of 60:40, (v/v) methanol and buffer. The column was maintained at a temperature of 30°C, with a flow rate of 1.0 mL/min. UV wavelength at 254 nm. The method exhibited high specificity and demonstrated linearity over the concentration range of 0.502–6.025 µg/mL, with a correlation coefficient (r²) greater than 0.999. Accuracy exceeded 97%. The method was validated in accordance with the guidelines established by the International Council for Harmonisation (ICH), covering parameters such as specificity, linearity, precision, accuracy, and robustness. Forced degradation studies revealed that Linezolid oral suspension was sensitive to acid and oxidative stress conditions. The developed method is considered suitable for routine quality control applications, including impurity profiling and stability-indicating analysis of Linezolid oral suspension.