Peel the banana(s) and cut them into ½-inch thick slices.
Line a baking sheet with parchment paper and lay the banana slices on the lined baking sheet in a single layer. Freezing the bananas individually first helps prevent them from sticking together in one large clump when frozen.
Freeze the bananas for 1-2 hours, or until solid, then transfer to an air-tight, freezer-safe container, like a freezer bag, glass meal prep container, or glass jar. Label the container with the contents and date.