Background/Aim: Dietary interventions like time-restricted feeding (TRF) show promising anti-cancer properties. We examined whether therapeutic TRF alone or combined with immunotherapy would diminish renal tumor growth in mice of varying body weights. Materials and Methods: Young (7 week) chow-fed or older (27 week) high-fat diet (HFD)-fed BALB/c mice were orthotopically injected with renal tumor cells expressing luciferase. After tumor establishment, mice were randomized to ad libitum feeding or TRF +/– anti-CTLA-4. Body composition, tumor viability and growth, and immune responses were quantified. Results: TRF alone reduced renal tumor bioluminescence in older HFD-fed, but not young chow-fed mice. In the latter, TRF mitigated tumor-induced loss of lean- and fat-mass. However, TRF did not alter excised renal tumor weights or intratumoral immune responses and failed to improve anti-CTLA-4 outcomes in any mice. Conclusion: Therapeutic TRF exhibits modest anticancer properties but fails to improve anti-CTLA-4 immune checkpoint blockade in murine renal cancer.