Background: Launaea pinnatifida (Willd.) Sch. Bip ex Kunze (Asteraceae) is an Indian Ocean intertidal sand dune herb that is useful as traditional medicine. The plant is one of the species of traditional Indian Ayurvedic herb “Gojihva.” Objectives: The present study was performed to isolate, characterize, and estimate a potential marker compound from L. pinnatifida. Materials and Methods: The leaves of the plant were subjected to successive solvent extraction with the help of solvents of varying polarity. Based on bioactivity studies performed using these extracts, the most bioactive methanolic extract was further subjected to vacuum liquid chromatography using chloroform and methanol in varying proportions. A phytoconstituent was isolated from fraction chloroform: methanol (90:10), elucidated to be Esculin based on its analytical (FTIR, liquid chromatography–mass spectrometry, 1H nuclear magnetic resonance, and ultraviolet) data. For the quantitative analysis of esculin in L. pinnatifida leaves, simple and validated high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods were developed. Results: The purity of isolated as well as purchased standard esculin was found to be 97.66% and 98.2%, respectively, by HPLC, whereas the yield of esculin in the methanolic extract of leaves was found to be 1.40% w/w by HPTLC. Conclusion: Esculin has been reported for the first time in this plant and can be considered a potent phytochemical marker. It can also be useful for the standardization and quality control of L. pinnatifida formulations.