N64 to Wii Adapter

There are 2 types of N64 to Wii adapter which you can buy.
One plugs into a Wii's GameCube ports, and the other plugs into the Wii Remote's extension port.

Which adapter do I need?

Console GameCube Adapter Wiimote Adapter
GameCube
Wii (RVL-001)
Wii Family Edition (RVL-101)
Wii mini (RVL-201)
Wii U *

* The Wii U has no GameCube controller ports of its own. A GameCube controller needs Nintendo's separate USB GameCube Controller Adapter, and Nintendo states that it can only be used in compatible games, currently only Super Smash Bros. for Wii U. It is not an option for Virtual Console games.
Console port information from Nintendo Support, Wii U adapter information from Nintendo Support.

Not all games work with both adapters

The GameCube Adapter emulates a GameCube controller, and the Wiimote Adapter emulates a Wii Classic Controller. Each one only works in games that accept the controller it emulates, so please check that the game you want to play will work with the adapter you are buying.

For example, original GameCube games will not work with the Wiimote Adapter.

Full features, stick correction settings, rumble behaviour and the tested compatibility list for each adapter are on its own product page: GameCube Adapter and Wiimote Adapter.

For the exact build you need, see N64 to Wiimote or N64 to GameCube.

Looking to go the other way, and use a GameCube controller on a real Nintendo 64? See the GameCube to N64 adapter page, the N64 Adapter, or the full EM Adapter range.