The synthesis of nanomaterials utilizing plant-derived bioactive compounds has garnered substantial attention in recent years due to its sustainability, biocompatibility, and environmental friendliness. Traditional chemical and physical synthesis methods often involve toxic reagents and high energy requirements, making them less desirable for biomedical and environmental applications. In contrast, plant bioactives such as flavonoids, polyphenols, alkaloids, and terpenoids serve as natural reducing, stabilizing, and capping agents in the formation of nanoparticles, offering a safer and more eco-conscious alternative. This chapter comprehensively discusses the latest techniques employed for synthesizing plant bioactive-based nanomaterials, including sol-gel, hydrothermal, microwave-assisted, ultrasound-assisted, and phytochemical-assisted green synthesis methods. Each method is examined with regard to its process efficiency, nanoparticle morphology, and suitability for scale-up. The unique physicochemical properties of the synthesized nanoparticles; such as high surface area, enhanced reactivity, and biological functionality, make them highly suitable for diverse applications. These include targeted drug delivery systems, antimicrobial and anticancer therapies, antioxidant and anti-inflammatory treatments, as well as environmental applications like pollutant removal and water purification. Agricultural uses such as nano-fertilizers and nano-pesticides are also explored, highlighting the broad-spectrum utility of these materials. Furthermore, the chapter critically addresses the key challenges associated with plant-based nanomaterials, including issues of scalability, reproducibility, shelf life, and regulatory compliance. Strategies to overcome these hurdles are discussed to support future research and industrial translation. By integrating current advancements and application prospects, this chapter serves as a valuable resource for researchers and professionals aiming to explore and expand the potential of plant bioactive-based nanotechnology across multiple domains.