Taupō Airport: The closest useful airport, but with limited domestic flights. Hire a car at the airport and drive roughly 1 hr 30 min–2 hr to Whakapapa Village; there is no dependable airport-to-village public-transport transfer. This is the sensible fly-in option only if the flight schedule works.
Auckland Airport: Hire a car and allow about 4 hr 15 min–5 hr, depending on conditions and stops. Auckland is the practical international gateway, not a place from which to attempt a same-day public-transport connection to the village.
Wellington Airport: Hire a car; expect roughly 4 hr 30 min–5 hr to Whakapapa Village. It is a viable alternative to Auckland for a North Island road trip, but not a quick transfer.
National Park railway station: The closest rail stop, around 25 km/25–35 minutes from Whakapapa Village by car. Treat rail as a scenic, schedule-dependent arrival rather than local transport: pre-arrange a pickup or taxi/shuttle before boarding, since services are sparse and do not run to hiking-hour convenience.