This research introduces an eco-friendly green Reverse-Phase High Performance Liquid Chromatography (RP-HPLC) method for detecting and quantifying meropenem trihydrate. Traditional methods use buffered solutions, gradient mobile phases, and longer retention times, but this method offers a rapid RP-HPLC technique with a C8 column and isocratic mobile phase (60% methanol, 40% ultra-pure water), eliminating the need for buffers and acetonitrile. It features a short 2.1-minute retention time and a high r² value of 0.9995. It delivers accuracy (101.1-102.3%) and precision (RSD ≤ 2%), coupled with low LOD and LOQ values of 1.72 and 5.20 µg/ml. Aqueous dilution simplifies sample preparation, reducing degradation and interference. The method is compared with an HPTLC method, showing an extended linear range (6.25-200 µg/ml for HPLC, 7.81-62.5 µg/ml for TLC) and high sensitivity, making it significant for meropenem trihydrate quality control in bulk and dosage forms.