In the Harry Potter film and book universe, the Ministry of Magic (M.o.M.) is the main governing body of the magical community of Great Britain and Ireland, with the intention of preservation of magical law. The Ministry connects the British government to the wizarding world. The headquarters of the Ministry are in Whitehall, in central London, deep underground.
The Ministry is headed by the Minister for Magic; throughout the books, it is generally depicted as either corrupt, incompetent, or both, with its high officials blind to actual events and dangers. It reaches a zenith of corruption before being effectively taken over by Lord Voldemort. At the end of the final book, following Voldemort’s death, Kingsley Shacklebolt takes over the ministry, changing it for the better. By the time of Harry Potter and the Cursed Child, in 2019, Hermione Granger is the Minister for Magic.
There are seven main Ministry departments: Magical Law Enforcement, Magical Accidents and Catastrophes, Magical Transportation, Mysteries, Magical Games and Sports, Regulation and Control of Magical Creatures, and International Magical Cooperation.