Casein kinase 1 (CK1) members play a critical and evolutionary conserved role in Wnt/β-catenin signaling. They phosphorylate several pathway components and exert a dual function, acting as both Wnt activators and Wnt inhibitors. Recent discoveries suggest that CK1 members act in a coordinated manner to regulate early responses to Wnt and notably that their enzymatic activity is regulated. Here, I provide a brief update of CK1 function and regulation in Wnt/β-catenin signaling.