Leftover Domino's pizza is generally safe to eat for 3–4 days when properly stored in the refrigerator at 40°F (4°C) or below. For best quality and taste, consume it within 2 days. Store it in an airtight container or wrap it tightly in foil or plastic wrap to prevent it from drying out and to protect it from absorbing odors from other foods.
If you want to keep it longer, you can freeze Domino's pizza for up to 2–3 months. Wrap individual slices or the whole box in freezer-safe wrapping to prevent freezer burn. Thaw frozen pizza in the refrigerator before reheating.
The main signs that leftover pizza has gone bad are visible mold, an off smell, or a sour taste. Pepperoni and other cured meats can mask spoilage longer than fresh toppings, but don't rely on this—when in doubt, throw it out.
To reheat, use an oven or toaster oven at 350°F for 5–10 minutes to restore crispness, or microwave for 30–45 seconds per slice (though this makes the crust softer). Avoid leaving pizza at room temperature for more than 2 hours, or 1 hour if the room is above 90°F, as bacteria multiply rapidly in the danger zone between 40°F and 140°F.