The creation of plant-based meat substitutes has advanced with the inclusion of new and sustainable sources for meat alternatives beyond traditional soy, pea and wheat proteins. Newer sources of proteins that are proposed include sacha inchi, duckweed, seeds of jackfruit, amaranth, quinoa, chia seeds, mycoproteins and seaweed. These possess wide nutritional values and functional properties necessary for the production of meat analogs. Sacha inchi seeds are particularly appealing as they are rich in protein and omega-3 fatty acids, which are essential for meat substitutes. An aquatic flowering plant with rapid growth, duckweed contains a complete amino acid composition alongside its protein value of about 45%. Jackfruit seeds, which are usually wasted, are a viable source of durable protein, being rich in starch and highly abundant. Pseudocereals with high protein content like amaranth and quinoa enhance the meat analogs’ mouthfeel and texture with their stomach-effecting amino acid profile. Chia seeds increase the oil and water absorption in plant-based meat products, thus enhancing their juiciness with their abundant protein and omega-3 content. Fungi such as Fusarium venenatum are known to have efficient and eco-friendly processes of fermentation, making mycoproteins excellent for meat-like textures as they mimic muscle fibres. Seaweed (red, brown and green algae) contains a high amount of protein and has shown potential as a valuable component in the development of meat analogs. Eco-friendly methods of deriving protein and reducing negative environmental impacts, as well as contributing towards the circular economy of food supply, can also be achieved with the aid of transforming agricultural and industrial waste into protein-rich constituents through microbial fermentation. These advancements not only diversify consumer options but also promote sustainability and nutritional adequacy in plant-based diets.