The Wnt signaling pathway is a critical regulatory mechanism that governs cell cycle progression, apoptosis, epithelial-mesenchymal transition (EMT), angiogenesis, stemness, and the tumor immune microenvironment, while also maintaining tissue homeostasis. Dysregulated activation of this pathway is implicated in various cancers, closely linked to tumor initiation, progression, and metastasis. The Wnt/(3-catenin axis plays a central role in the pathogenesis of common cancers, including colorectal cancer (CRC), breast cancer (BC), liver cancer, and lung cancer. Unlike traditional chemotherapy, targeted therapy offers a more precise approach to cancer treatment. As a key regulator of oncogenesis, the Wnt pathway represents a promising target for clinical interventions. This review provides a comprehensive analysis of the Wnt signaling pathway, exploring its roles in tumor biology and its implications in human malignancies. It further examines the molecular mechanisms and modes of action across different cancers, detailing how the Wnt pathway contributes to tumor progression through mechanisms such as metastasis promotion, immune modulation, drug resistance, and enhanced cellular proliferation. Finally, therapeutic strategies targeting Wnt pathway components are discussed, including inhibitors targeting extracellular members, as well as those within the cell membrane, cytoplasm, and nucleus. The potential of these targets in the development of novel therapeutic agents underscores the critical importance of intervening in the Wnt signaling pathway for effective cancer treatment.