**Abstract**

Graphene oxide is a two-dimensional material formed from oxidized graphite, with oxygen (O) functional groups decorating the *sp*2 plane of carbon (C). Graphene oxide can be obtained by exfoliating the graphite oxide (oxidized three-dimensional carbonbased material) into the layered sheets by sonication or mechanical stirring. Graphene oxide contains various reactive oxygen functional groups, which make it to be a good candidate as a foundation in many applications, such as polymer composites, materials for energy conversion, environmental applications, sensors, FET transistors, and photonic applications, due to its excellent electrical, mechanical, and thermal properties. The widely used technique to synthesize graphene oxide is the modified Hummer's method because of its simple process, low cost, and high yield. In this chapter, we report the progress of graphene oxide synthesis using graphite from activated carbon gathered from biomass waste as the source instead of commercial graphite. The chapter covers the synthesis of biomass waste-based graphene oxide and future perspective applications of graphene oxide. Scientific reports about biomass waste-based graphene oxide synthesis and recent applications of graphene oxide will be discussed. The main motivation for writing this chapter is to bring to the horizon the utilization of biomass waste as an alternative carbon source for the green, low-cost, and sustainable production of graphene oxide.

**Keywords:** biomass waste, activated carbon, graphene oxide, Hummer's method
