Multicellular structures formed by yeasts have long served as valuable models for studying essential processes such as cell–cell communication, signaling, and cell differentiation—key processes in the development of multicellular organisms. This review summarizes current knowledge on the formation and internal organization of two types of spatial multicellular structures formed by the yeast Saccharomyces cerevisiae: colonies and biofilms. Both structures develop on semisolid or solid surfaces and, as in metazoans, arise through the division and differentiation of non-motile cells. We highlight the distinct subpopulations of differentiated cells that emerge within these structures and describe their spatial organization, interactions, metabolic profiles, and functional roles in colonies and biofilms. We also discuss the regulatory pathways involved in colony and biofilm development and cell differentiation. In colonies, these include mitochondrial signaling pathways and factors such as TORC1, Gcn4, and Whi2, as well as pathways driving site-specific sporulation. Key factors driving biofilm formation include the extracellular matrix and the adhesin Flo11, along with critical regulators such as Cyc8 and Tup1.