If you have a bottle of “maple syrup” – ie. the commercial type you buy for cheap in the grocery store, this can be stored in the cupboard, but if you have space in the refrigerator, it will last longer. But as always, double check the label for storage instructions. If it doesn’t state refrigerator, then storing it in the cupboard is fine.
However, if it is PURE maple syrup, they actually recommend that you store it in the freezer if you will be going long periods without using it, and surprisingly, it will not freeze solid. Otherwise, store pure maple syrup in the refrigerator.