Biomolecular condensates are membraneless compartments that organize cellular activities by selectively concentrating molecules into dynamic, reversible assemblies. Once thought to be a eukaryotic innovation, condensates are now recognized as a broadly distributed compartmentalization strategy, shaped by conserved physical principles and adapted across diverse microbial lineages. In this review, we examine how condensates operate across the microbial domains of life, revealing a modular framework where shared biophysical rules are tuned by evolutionary forces to meet distinct cellular demands. Understanding the interplay between constraint and innovation deepens our view of microbial cell biology and enables the design of programmable condensates for synthetic applications.