The ErbB2 signaling pathway plays a crucial role in cancer stem cells (CSCs), governing cancer aggressiveness and proliferation. Targeting ErbB2 holds promise for advancing cancer therapeutics. Resveratrol (RES) and its derivatives have been noted for their ability to target proteins that are involved in CSCs. In this investigation, we synthesize novel derivatives of RES, aim at elucidating structure-activity relationships (SARs) that could enhance the anticancer properties of the RES analogues, and explore their capacities to suppress CSCs. YI-12, an O-benzyl-substituted 1,3-diphenylpropane, demonstrated the most potent anticancer activity against lung cancer cells (A549 and H460), showing high potential inhibiting cancer colony formation. Interestingly, not only does YI-12 suppress CSCs-related proteins, indicated by decreased expression of CSC-enhancing molecules such as CD133-, OCT4-, and CSC-related protein β-catenin, but it also induces apoptosis in CSC-rich spheroids after treatment. Additionally, molecular docking and bioinformatic analysis suggest ErbB2 as a potential target of the compound with a strong binding affinity (-6.709 kcal/mol) compared to the reference compound TAK-285 (-5.563 kcal/mol). YI-12's capability to bind and inhibit ErbB2 leads to the suppression of PI3K and AKT. In conclusion, we highlight the novel resveratrol derivative YI-12 for its ability to inhibit CSCs through the ErbB2 signaling pathway. This compound represents a promising structure that should be further developed for potential use in anticancer therapy.