The United National Heavyweight Championship (often shortened to UN Championship) is a professional wrestling title in Japanese promotion Pro Wrestling Zero1. It is one of Zero1's top two singles titles, along with the Zero1 World Heavyweight Championship. The UN title was created on January 31, 2004, when Masato Tanaka defeated Steve Corino in an Indian strap match, wrestling as Masa Tanaka. It was founded at a time when Zero1 was a member of the National Wrestling Alliance; since the two organizations' parting in late 2004, the NWA does not recognize or sanction it, though it retains the NWA initials.
- Pro Wrestling Zero1
- National Wrestling Alliance
- Zero1 World Heavyweight Championship
- Zero1 International Junior Heavyweight Championship
- NWA Intercontinental Tag Team Championship
- NWA International Lightweight Tag Team Championship
- Zero-One United States Heavyweight Championship