The Ontario Municipal Board (OMB) was a powerful provincial tribunal that heard appeals on planning and development matters, often overturning municipal council decisions. The OMB had authority to substitute its own judgment for municipal decisions, leading to criticism that it undermined local democracy. In 2017, the OMB was replaced by the Local Planning Appeal Tribunal (LPAT), with reforms reducing appellant ability to override municipal decisions. LPAT has since been merged into the Ontario Land Tribunal. The OMB's history illustrates ongoing tensions between provincial oversight, development interests, and local planning authority in Ontario's planning system.