Background: Methotrexate (MTX) is one of the utmost commonly prescribed drugs, which is official in the IP, BP, and USP. MTX is a potent drug that can cause serious side effects if not used in the correct quantity. Assaying MTX is vital to guarantee that the drug exists in the required concentration in the sample. Developing a simple, rapid, and cost-effective analytical tool for its estimation has always been a thrust area of research. In this line, this investigation reports a simple, rapid, and low-cost Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) method with an ultraviolet detection channel for estimating MTX in bulk samples. Materials and Methods: The technique employs an isocratic mobile phase comprising a readily available solvent system having 50 mM sodium acetate buffer (pH-3.6) and acetonitrile in 90:10, v/v, which flows through the column at a constant flow rate of 1.0 mL/min. A Thermo C-18 Column (5-micron, 250 mmx4.60 mm) was used as the stationary phase for separation. Considering the optimized chromatography parameters, sensitivity, and selectivity of a method for drugs, 307 nm was selected as the detection wavelength for the UV-visible detector. The validation studies were performed by fulfilling the requirements of ICH guidelines. Results and Conclusion: The method was found to be specific, linear (including intra-and inter-day precision), accurate, and precise for routine testing of MTX. The developed RP-HPLC method has been successfully applied to determine MTX in standard Laboratory Bulk samples and commercial Dosage Formulations, as well as to monitor the release kinetics of MTX from an in-house developed Nanoformulation. The developed method represents a valuable tool in the laboratory analysis and monitoring of MTX during routine quality control testing and toxicity studies.