Nowadays, the interest of the world toward nanocellulose materials has been incredibly increased for the development of high value products owing to the unique and potentially convenient structures of nanocellulose. There is advanced enhancement of the nanocellulose application with strongly increasing interest for the high demand of sustainability requirements in the global market. Nanocellulose materials are sourced from different plant fibers, algae, tunicate and bacteria. They have been synthesized through different extraction techniques like acid hydrolysis, and mechanical refining methods with increasing advancements. Nanocellulose products have potential application areas of reinforcements in nanocomposites, paper and packaging industries, biodegradable films, barriers in packaging and membrane industries, additives in food and medical applications, and medical devices, wound healing, bioactive implants and self-healing applications. This review realizes the current understandings of nanocellulose materials with source materials, isolation techniques from their sources, extraction methods and end use applications.