Nagaoka is a lunar impact crater that lies to the southeast of the Mare Moscoviense, on the far side of the Moon.

The remainder of the rim remains well-defined, although it is overlain by several tiny craters.

The inner wall has slumped in places, forming terrace-like shelves.

The crater was named after Japanese physicist Hantaro Nagaoka by the IAU in 1970.

[1] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Nagaoka.