The Maguindanao massacre, also known as the Ampatuan massacre, named after the town where mass graves of victims were found, occurred on the morning of November 23, 2009, in the town of Ampatuan in Maguindanao province, on the island of Mindanao in the Philippines. The 58 victims were on their way to file a certificate of candidacy for Esmael Mangudadatu, vice mayor of Buluan, when they were kidnapped and later killed. Mangudadatu was challenging Datu Unsay mayor Andal Ampatuan Jr., son of the incumbent Maguindanao governor Andal Ampatuan Sr. and member of one of Mindanao's leading Muslim political clans, in the forthcoming Maguindanao gubernatorial election, part of the national elections in 2010. The people killed included Mangudadatu's wife, his two sisters, journalists, lawyers, aides, and motorists who were witnesses or were mistakenly identified as part of the convoy.

The Committee to Protect Journalists (CPJ) has called the Maguindanao massacre the single deadliest event for journalists in history. At least 34 journalists are known to have died in the massacre. Even before the Maguindanao massacre, the CPJ had labeled the Philippines the second most dangerous country for journalists, second only to Iraq.