In the last decade, landfill technologies have globally changed with the enforcement of recycling strategies in sustainable waste management practices. Simultaneously, the waste-to-energy concept has evolved through implementation of advanced technologies for energy recovery from the landfill. This chapter deals with the transition of conventional landfills to different modes of landfill bioreactors (LBRs). The elucidation of microbiological advancement using cutting edge genomics and metagenomics approaches is described. The initiatives of government policies and legislation are discussed both at the international and national (Oman) level. The recent improvement in advanced LBRs processes, modelling, and simulation for landfill gas recovery, physical and chemical parameter analysis and landfill stabilization are reported. The in-depth knowledge and understanding of LBRs behaviour enable the policymakers and stakeholders for formulation and enforcement of appropriate environmental laws under sustainable waste management. © 2019 Nova Science Publishers, Inc.