The sugar industry is a major setup in the world and generates large amounts of wastes. Sugarcane bagasse, tops, press mud, molasses, wastewater, etc., are some wastes generated during different steps of sugar production. These wastes are not only difficult to manage, but also improper disposal of them has a negative impact on the environment. Since these wastes contain a lot of organic material, different technologies for valorization are being developed to produce marketable goods at a reasonable cost, especially chemicals and biofuels. Due to the high lignocellulosic content of these wastes, many pretreatment techniques and technologies have been developed in the recent past. Furthermore, to release simple sugars, pretreated biomass is primarily subjected to enzymatic saccharification. Fermentation of these simple sugars by different classes of microbes leads to the production of various chemicals and biofuels of economic importance. The use of molasses to make ethanol is one of the key advancements in the value-adding of sugar industry leftovers. Bagasse has started to be used to generate electricity for the national grid and to meet the energy needs of the sugar industry. These two developments not only provide an environmentally clean energy source but also help developing nations economically. With the continued research on the development of diverse methods and technologies for the valorization of sugar industry wastes, biohydrogen, bioplastics, organic acids, fertilizers, etc. have been the valuable products generated successfully.