Raloxifene hydrochloride (RLX) belongs to the Selective estrogen receptor modulator (SERM) class of drugs, exhibiting diverse affinity to estrogen receptors. The drug is known for its anti-cancer and anti-osteoporosis activity. The current study employs a Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method that is sensitive and time-efficient for quantitative evaluation of RLX from mice plasma, using tamoxifen citrate as an internal standard (IS). The protein precipitation technique was used to extract the RLX and IS. RLX was separated using a C8 column with an isocratic elution of a mobile phase consisting of acetonitrile and Milli-Q water (pH 3) at a 1 mL/min flow rate. The ultraviolet (UV) detection of the analyte and IS were carried out at 287 nm. The linearity plot was constructed in the range of 100–3200 ng/mL with a correlation coefficient of r2 ≥ 0.9996. The inter-day and intra-day accuracy and precision were found to be within acceptable limits. Stability studies revealed that the analyte remained stable. The validated RP-HPLC method was successfully applied to quantify RLX after oral administration in mice, and the pharmacokinetic (PK) parameters were established. The present RP-HPLC method could be a beneficial tool for the fast and reliable estimation of future PK interactions, PK analysis of formulations, and therapeutic drug monitoring.