Which Wikipedia policy requires a neutral point of view?

The Wikipedia policy that requires a neutral point of view is the Neutral point of view policy.

Often abbreviated NPOV, it requires articles to represent significant viewpoints fairly, proportionately, and without editorial bias. The policy does not mean that every opinion receives equal space. Instead, coverage should reflect the prominence and reliability of the available sources, while clearly distinguishing established facts from attributed opinions and disputes.

Neutral point of view is one of Wikipedia’s core content principles and is closely connected to Verifiability and No original research. Verifiability asks whether readers can check claims in reliable sources; no original research prohibits editors from introducing their own unpublished conclusions. NPOV governs how sourced material is presented once it is included.

Readers sometimes confuse neutrality with pretending that controversies do not exist. Wikipedia can describe competing interpretations, criticism, and minority views when reliable sources give them meaningful coverage. The goal is not to make every article completely free of disagreement, but to describe the disagreement accurately and in proportion to the evidence and attention it has received.