Acute lymphoblastic leukemia (ALL) has high relapse rates, requiring new therapies. Quercetin, a natural flavonoid, exhibits anti-cancer potential, but its mechanisms in ALL, particularly involving miRNAs, are unclear. This study explores quercetin's effects and its role in regulating the miR-367/KLF4/JNK axis. Using ALL cell lines and xenograft models, quercetin's efficacy was assessed. It inhibited tumor growth in mice and induced apoptosis and autophagy in vitro. Mechanistically, quercetin downregulated miR-367, leading to upregulation of KLF4, which subsequently suppressed JNK signaling to promote cell death. In vivo results confirmed that quercetin suppresses ALL progression via this pathway. These findings identify quercetin as a potent anti-leukemic agent targeting the miR-367/KLF4/JNK axis to induce cell death. This reveals a novel regulatory pathway in ALL and highlights quercetin's potential as a miRNA-based therapy.