- The Maguindanao massacre, also known as the Ampatuan massacre after the town where the mass graves were found, occurred on the morning of 23 November 2009, in the town of Ampatuan in Maguindanao province, on the island of Mindanao in the Philippines.
- 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.
- On 4 December 2009, through Proclamation No. 1959, President Gloria Macapagal Arroyo officially placed Maguindanao province under a state of martial law, thereby suspending the privilege of the writ of habeas corpus.
- The state of martial law in Maguindanao was lifted on 13 December 2009.
- ProTest Broadcast 3, a concert series held in 2010 for the benefit of the families of the journalists killed in the Maguindanao massacre, organized by Bread Society International in cooperation with Breakthrough and Milestones Productions and UNTV. The dates of the concert tour were held on 17 May 2010 in Araneta Coliseum, Araneta Center, Quezon City; 23 May 2010 at Cebu Convention Center; and 30 May 2010 at the CAP Auditorium in Davao.
- History Asia premiered a documentary on the Maguindanao massacre entitled The Maguindanao Massacre on 26 September 2010.
- On 16 November 2010, the international non-governmental organization Human Rights Watch issued a 96-page report titled "They Own the People" which links the Ampatuans to at least 56 other killings over the last 20 years, apart from the November 23, 2009, massacre charting the Ampatuans’ rise to power, including their use of violence to expand their control and eliminate threats to the family’s rule.
- In July 2014, in memory of the five-year anniversary of the massacre, Sacramento-based author Victoria Conlu also released a novel titled Portraits of a Massacre, a fictionalized telling of a province similar to Maguindanao, reviewed as "a stirringly severe literary intervention".
- Quezon City Regional Trial Court Branch 221 Judge Jocelyn Solis-Reyes issued a release order for the brother of primary suspect Andal Jr., Sajid Islam, who is also the son of clan patriarch and former Maguindanao governor Andal Ampatuan Sr, through lawyer Gregorio Marquez, posted the surety bond amounting to P11.6 million in exchange for his temporary release.
- Andal Ampatuan Sr. who had been in the hospital since June 2015 after being diagnosed with cirrhosis of the liver succumbed at 10:02 p.m. on 17 July 2015 despite efforts to revive him, according to a Discharge Summary report by the National Kidney & Transplant Institute. He allegedly led the planning and execution of the massacre of the members of the convoy of the wife of then Maguindanao province gubernatorial candidate Esmael “Toto” Mangudadatu.
- Branch 221 Judge Jocelyn Solis-Reyes of the Quezon City Regional Trial Court denied the petitions for bail of former Autonomous Region in Muslim Mindanao Gov. Zaldy Ampatuan, last 15 September 2015.
- A concert on 22 November (23 November in the Philippines), Sunday, at the Celebrity Centre International in Los Angeles, entitled “Abakada: Children Helping Children,” and produced by NUJP-US (National Union of Journalists of the Philippines in the United States Chapter (NUJP-US)) in partnership with the Filipino American Press Club of California, F7 Photographers, Frontliners, Philippine Press Photographers (PPP)-USA, and Pen and Lens Press Club, where a photo exhibit has also been set up as a benefit concert for the orphans of the 32 journalists killed in the 2009 Ampatuan Massacre.