LocalWiki is a nonprofit grassroots project that helps people collect, share, and preserve knowledge about the places where they live. Its collaborative online platform serves as a community knowledge commons, bringing together information about neighborhoods, parks, local history, politics, family life, and other topics that matter to residents. Anyone can read, add, or edit pages, making it possible for neighbors to build a shared account of their community without technical expertise or academic credentials.

Communities around the world use LocalWiki, with content spanning thousands of regions and multiple languages. The organization also provides a geospatially aware, read-write API, enabling developers to connect applications with LocalWiki or import useful local data. The platform is free to access, copy, and reuse, and its underlying software is open source. LocalWiki describes its work as a public good, comparable to a park or public library, and operates without advertising. It is supported by donations and invites communities to bring LocalWiki to their area, contributing to a global, openly accessible resource for local knowledge.