Andrographis paniculata (Burm.f.) Wall. ex Nees is a plant of significant interest in various studies due to its potential therapeutic properties and applications in traditional medicine. This is a medicinal herb found in Asian countries, utilized in various traditional medicinal systems for addressing conditions such as diarrhea, flu, leprosy, leptospirosis, malaria, rabies, upper respiratory infections, sinusitis, syphilis, tuberculosis, and HIV/AIDS, among others. This chapter seeks to deliver thorough, precise, and reliable information regarding the traditional applications, phytochemical composition, and pharmacological characteristics of different extracts and fractions, along with the phytoconstituents of A. paniculata. Terpenoid lactones and flavonoids represent the primary bioactive classes of compounds found in A. paniculata, contributing to its pharmacological properties, including anticancer and antioxidant activities. Various activities such as analgesic, anticancer, antidiabetic, antifertility, anti-inflammatory, antimalarial, antimicrobial, antioxidant, antipyretic, antiviral, antiretroviral, antivenom, cardioprotective, hepatoprotective, immunomodulatory, and neuroprotective have also been documented. Andrographolide serves as a significant active compound and is accountable for the majority of the pharmacological effects observed. Compelling evidence demonstrated that the pharmacological activities observed in crude extracts and chemical markers reinforce and instill confidence in the traditional application of A. paniculata as a herbal remedy.