The Waitangi Tribunal (Māori: Te Rōpū Whakamana i te Tiriti o Waitangi) is a New Zealand permanent commission of inquiry established under the Treaty of Waitangi Act 1975. It is charged with investigating and making recommendations on claims brought by Māori relating to actions or omissions of the Crown, in the period largely since 1840, that breach the promises made in the Treaty of Waitangi. The Tribunal is not a court of law; therefore, the Tribunal's recommendations and findings are not binding on the Crown. They are sometimes not acted on, for instance in the foreshore and seabed dispute.

The inquiry process contributes to the resolution of Treaty claims and to the reconciliation of outstanding issues between Māori and Pākehā. In 2014, the Tribunal found that Ngāpuhi rangatira did not give up their sovereignty when they signed the Treaty of Waitangi in 1840.

In 1975, protests from Māori about unresolved Treaty of Waitangi grievances had been increasing for some time, and the Tribunal was set up to provide a legal process for the investigation of those grievances. Matiu Rata, a Minister of Māori Affairs in the early 1970s, took a leading role in the Tribunal's creation.

Originally the Tribunal could investigate grievances only since 1975, but in 1985, a law change meant the Tribunal's jurisdiction was extended back to 1840, the date of the Waitangi Treaty. The subsequent findings of many Treaty breaches by the Crown in various inquiries led to a public backlash against the Tribunal. The Tribunal has often been a political issue in the 1990s and 2000s.

Originally a Tribunal investigation and report was a prerequisite for a Treaty settlement, but in 1999, to speed up settlements, parliament changed the process so that claimants could go straight to settlement with the Office of Treaty Settlements without engaging in the Tribunal process. This was an increasingly popular short-cut to settlement in the face of the slow Tribunal process. The deadline for submitting historical claims was 1 September 2008, but contemporary claims can still be filed.

In late October 2024, the Government appointed retired cabinet minister Richard Prebble and senior insurer Ken Williamson to the Tribunal. Kevin Prime was reappointed for a second term. Labour Member of Parliament Willie Jackson objected to Prebble's appointment, citing his alignment with the ACT Party's policies towards Māori including the controversial Treaty Principles Bill.

On 17 January 2025, Minister for Māori Development Tama Potaka announced an overhaul of the Waitangi Tribunal's membership. He appointed eight new members including Rangitāne Tū Mai Rā Trust general manager Tipene Crisp, lawyer and New Zealand On Air board member Philip Crump, Ngāti Raukawa Treaty negotiator Vanessa Eparaima, veteran public servant Rex Edward Hale, Manawatū District Councillor Grant Hadfield, Tupuora Education founder and managing director Kingi Kiriona, former Defence Minister and Mayor of Carterton Ron Mark, and University of Waikato law Professor Tafaoimalo Leilani Tuala-Warren. In addition, Potaka renewed the warrants of six existing Tribunal members including Ruakere Hond, Derek Fox, Kim Ngārimu, Hana O'Regan, Pou Temara and Kevin Prime. Ten members including Linda Tuhiwai Smith, Tom Roa, Rawinia Higgins, Herewini Te Koha, Prue Kapua, Monty Soutar, Ron Crosby, Robyn Anderson, Tania Simpson and Grant Phillipson did not have their terms renewed. Te Pāti Māori co-leader Debbie Ngarewa-Packer described the removal of several well known Māori academics as a "whitewash." In response, Potaka said that Ngarewa-Packer's comments were "unhelpful" and undermined the knowledge and experience of the new appointees.

On 9 May, Potaka announced that an "independent technical advisory group" would review the Treaty of Waitangi Act 1975, which governs the scope of the Waitangi Tribunal. This review was part of the Sixth National Government's coalition agreements with the ACT and New Zealand First parties to review the scope of the Waitangi Tribunal.