Al-khumus is a religious obligation in Islam that requires individuals to donate one-fifth of their annual increase in wealth to charitable causes. In the pursuit of innovative fiscal solutions for sustainable development challenges, al-khumus represents a significant underutilisation of traditional mechanisms, which could be reimagined as a modern funding source. The objective of this study is to review al-khumus as a potential contemporary viable fiscal solution for sustainable development. This study utilised a review analysis methodology to investigate the feasibility of al-khumus as a modern fiscal solution for sustainable development. The literature inclusion criteria emphasised studies published in the past twenty years that examined the principles of al-khumus, its historical importance, and its relevance in modern fiscal systems. The review analysis revealed a few viable fiscal solutions of al-khumus for sustainable development, namely: (a) increased government revenue; (b) reduced poverty and inequality; (c) sustainable economic growth; and (d) enhanced social welfare. In conclusion, this study highlights the potential of al-khumus as a viable fiscal solution for sustainable development, emphasising its alignment with ethical funding principles and its role in fostering social solidarity within Muslim communities. Further studies on this topic should involve empirical investigations to evaluate the practical implementation of al-khumus across diverse economic contexts, especially in nations with significant Muslim populations.