<p>This review provides a comprehensive summary of recent advancements in biodiesel development, integrating bibliometric, techno-economic, and environmental perspectives. Biodiesel has emerged as a sustainable alternative to fossil fuels, and the growing international energy demand has made its production increasingly attractive. Feedstock selection remains a critical factor, encompassing first-generation edible oils, second-generation non-edible oils, third-generation algal biomass, and waste-derived sources. The analysis highlights issues related to land-use change, food-versus-fuel competition, and carbon debt. Technological progress has been achieved through transesterification, supercritical methods, and ultrasound- and microwave-assisted processes, all of which have improved conversion efficiency. Innovations have also introduced furnace-type, homogeneous, heterogeneous, and enzyme-based catalysts. However, these systems present challenges concerning catalyst reusability, soap formation, glycerol recovery, and NOx emissions. Life cycle assessments and greenhouse gas (GHG) modeling reveal key ecological trade-offs, while economic evaluations emphasize the need for more realistic estimates of commercial scalability. Operational limitations such as oxidative instability, low-temperature performance, and reduced flow yields continue to hinder standardization and large-scale deployment. Future directions focus on hybrid catalysts, integrated biorefineries, microalgae-based closed-loop systems, and decentralized processing. As supported by recent studies, implementing carbon–neutral cultivation and circular bioeconomy principles offers the most promising pathway toward sustainable biodiesel production.</p> Graphical Abstract <p></p>