The unrestrained discharge of huge quantities of food waste (FW) has been listed as a severe problem contributing to environmental pollution, especially in developing countries. In this context, the anaerobic digestion (AD) of FW is a promising technology in generating biogas for the increasing rise in energy outreach as well as the circular economy. The high metabolic activity of anaerobic microbes in AD is optimized through the control of temperature, pH, retention time, carbon-to-nitrogen ratio, formation of volatile fatty acid (VFA), and reactor design. However, among the succeeding digestion steps, hydrolysis is known to be the rate-limiting phase. This study presents a critical review of several physical, thermochemical, biological, or combined pre-treatments for improving methane yield AD. Additionally, another promising technique for enhancing the AD performance and reactor stability is co-digestion of FW with different organic feedstocks, as established in various research studies, with sophisticated buffering potentials and an optimal balance of nutrients for improving the reactor stabilities for improved biogas/methane yields of the anaerobic co-digestion (ACoD) has been studied and reviewed.