Recently, the use of composite materials has significantly increased in various industries, ranging from automotive to construction, due to their more advantageous properties compared to traditional materials. Nevertheless, with the growing environmental and ecological awareness, researchers are focusing on developing more environmentally friendly and healthier bio-composites while ensuring high-performance, affordable, renewable, biodegradable, and lightweight materials with environmental benefits. This literature review intends to provide an overview of recent work that focuses on bio-composites and bio-hybrid composites with natural reinforcements. Moreover, it presents the natural fillers, their classifications, the cultivation of some plants, their mechanical and chemical characteristics, as well as their potential applications. Additionally, this work describes the modeling, its different approaches, as well as the selection process of a model.