Multicomponent reactions (MCRs) have gained significant attention in the field of organic synthesis due to their ability to efficiently construct complex molecular structures in a single step. Among the reagents employed in MCRs, Meldrum's acid has emerged as a highly versatile and valuable starting material, offering a wide range of molecular diversity. This comprehensive review explores the molecular diversity scope of Meldrum's acid in various MCRs, focusing on its unique attributes and the greener aspects of its application. Meldrum's acid possesses several remarkable features that contribute to its suitability as a key component in MCRs. Its high acidity enables effective participation in a variety of chemical reactions, while its rigid structure provides stability and allows for precise control of the reaction pathways. Furthermore, the ability of Meldrum's acid to undergo both nucleophilic and electrophilic attacks makes it highly versatile in the construction of diverse molecular frameworks. Its low steric hindrance further enhances its reactivity, facilitating efficient bond formation. By surveying the literature from the last five years (2018–2022), we delve into the broad range of applications of Meldrum's acid in MCRs. The review encompasses the synthesis of various heterocyclic compounds, highlighting the significance of Meldrum's acid in achieving molecular diversity. Moreover, particular emphasis is placed on the greener aspects of utilizing Meldrum's acid, considering the growing demand for environmentally friendly synthetic approaches. This includes exploring greener solvents, milder reaction conditions, and reduced waste generation.