The anticancer activity of malvidin was studied in Dalton's lymphoma ascites (DLA)-induced solid and ascitic tumor mice models. Malvidin is a natural compound belonging to the family of O-methylated anthocyanidin and plays a predominant role in regulating both short- and long-term cellular activities. Animals were injected with DLA cells (1.5 × 106 cells/animal) to induce solid and ascitic tumors. The administration of malvidin (5 mg/kg bw and 10 mg/kg bw) was carried out for 10 consecutive days from the day of tumor induction for both solid and ascitic tumors. Cyclophosphamide, CTX (25 mg/kg bw), used as the standard drug, was also administered for 10 consecutive days. Treatment with malvidin showed a significant reduction in tumor volume and elevated white blood cell (WBC) count when compared to the DLA-bearing control animals. The treatment also maintained the body weight and hemoglobin level, and decreases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) were also noted. This investigation also reported the decreased levels of cellular glutathione (GSH) in ascitic tumor groups. Malvidin reduced inflammatory mediator and cytokine levels, such as tumor necrosis factor level alpha (TNF-α) and interleukin-6 (IL-6), which serve as molecular targets for cancer prevention. A decrease in the level of reactive oxygen species (ROS), like nitric oxide (NO), was observed. Histopathological examination revealed altered morphological changes in tumor tissue and the alleviation of hepatic architecture due to DLA. Immunohistochemical analysis revealed the inhibition of iNOS. This study demonstrated that malvidin exhibited significant in vivo antitumor activity and that it was reasonably imputable to its increasing endogenous mechanism. We accent the pertinence of malvidin as a potential naturally derived drug target for tumor control.