The extraction of bioactive compounds from medicinal plants plays a pivotal role in the development of pharmaceutical, nutraceutical, and cosmetic products. Conventional extraction methods, although widely used, often suffer from limitations such as prolonged extraction times, high solvent consumption, and degradation of thermolabile compounds. Ultrasonic-assisted extraction (UAE) has emerged as a green, efficient, and scalable alternative, leveraging acoustic cavitation to enhance mass transfer and disrupt plant cell walls. This review comprehensively discusses the fundamental principles of UAE, including the role of ultrasonic frequency, power intensity, solvent type, and extraction duration. Comparative analysis with traditional techniques demonstrates UAE’s superiority in terms of yield, time efficiency, and energy conservation. Recent advancements in reactor design, hybrid systems, and statistical optimization (e.g., response surface methodology) are highlighted. Limitations related to equipment scale-up, process reproducibility, and bioactive stability are critically addressed. Finally, future directions include the use of green solvents and AI-driven modeling for industrial-scale optimization. This review provides researchers and industry stakeholders with an in-depth understanding of UAE as a sustainable, high-performance technology for the extraction of medicinal plant bioactive.