β-Catenin is a multifunctional molecule that plays crucial roles in developmental and homeostatic processes in metazoans. It serves as a structural component of cadherin-based adherens junctions and as a key nuclear effector of canonical Wnt signaling. Imbalance in β-catenin's structural and signaling properties often leads to diseases and deregulated growth, including cancer and metastasis. The complex regulation of β-catenin involves interactions with various transcription factors and other signaling pathways. This review highlights the structural composition of β-catenin, its roles in cell adhesion and signaling, and the mechanisms that regulate its function, including phosphorylation and nuclear import/export. The review also discusses the evolutionary conservation of β-catenin and its functions in early metazoans, as well as its involvement in epithelial-mesenchymal transition (EMT) and centrosomal cohesion.β-Catenin is a multifunctional molecule that plays crucial roles in developmental and homeostatic processes in metazoans. It serves as a structural component of cadherin-based adherens junctions and as a key nuclear effector of canonical Wnt signaling. Imbalance in β-catenin's structural and signaling properties often leads to diseases and deregulated growth, including cancer and metastasis. The complex regulation of β-catenin involves interactions with various transcription factors and other signaling pathways. This review highlights the structural composition of β-catenin, its roles in cell adhesion and signaling, and the mechanisms that regulate its function, including phosphorylation and nuclear import/export. The review also discusses the evolutionary conservation of β-catenin and its functions in early metazoans, as well as its involvement in epithelial-mesenchymal transition (EMT) and centrosomal cohesion.