Lung cancer (LC) is the leading cause of cancer-related deaths globally. It accounts for more than 1.9 million cases each year due to its complex and poorly understood molecular mechanisms that result in unregulated cell proliferation and metastasis. β-Catenin is a developmentally active protein that controls cell proliferation, metastasis, polarity and cell fate during homeostasis and aids in cancer progression via epithelial–mesenchymal transition. Therefore, inhibition of the β-catenin pathway could attenuate the progression of LC. Berberine, an isoquinoline alkaloid which is known for its anti-cancer and anti-inflammatory properties, demonstrates poor solubility and bioavailability. In our study, we have encapsulated berberine into liquid crystalline nanoparticles to improve its physiochemical functions and studied if these nanoparticles target the β-catenin pathway to inhibit the human lung adenocarcinoma cell line (A549) at both gene and protein levels. We observed for the first time that berberine liquid crystalline nanoparticles at 5 µM significantly attenuate the expression of the β-catenin gene and protein. The interaction between berberine and β-catenin was further validated by molecular simulation studies. Targeting β-catenin with berberine nanoparticles represents a promising strategy for the management of lung cancer progression.