A rapid, sensitive, and accurate ultra-fast liquid chromatographic method is developed for the determination of related substances and degradants of Solifenacin Succinate, an active pharmaceutical ingredient used in the treatment of overactive bladder. Chromatographic separation of Solifenacin Succinate, its related substances, and degradants was achieved using a Shimpack XR-ODS-II column and mobile phase system containing 10 mM potassium dihydrogen orthophosphate in water. The pH of the buffer was adjusted to 7.0 using triethyl amine (mobile phase A). LC-grade acetonitrile was used as mobile phase B, employing a binary-gradient program at a flow rate 0.5 mL/min. The resolution between the critical pair of peaks (Impurity A and analyte) was found to be greater than 3.5. The limits of detection and quantification (LOQ) of Impurity A, Impurity B, and the analyte were 0.2 and 0.6 μg/mL, respectively for a 5-μL injection volume. The percentage recovery of impurities in the presence of sample matrix ranged from 95 to 104 w/w. The test solution and mobile phase was observed to be stable up to 24 h after the preparation. The validated method yielded good results of precision, linearity, accuracy, robustness, and ruggedness. The proposed method is found to be rapid, accurate, and suitable for the quantitative determination of related substances and degradants during quality control of Solifenacin Succinate active pharmaceutical ingredient.