1991 in the Philippines

• President: Corazon Aquino (PDP-Laban)
• Vice President: Salvador Laurel (UNIDO)
• President of the Senate: Jovito Salonga
• Speaker of the House of Representatives: Ramon Mitra, Jr.
• Chief Justice: Marcelo Fernan
• Philippine Congress: 8th Congress of the Philippines

• January 29 – Merger of the Philippine Constabulary with the Integrated National Police to form the Philippine National Police.
• February 10 – Lenny Villa, a first-year Ateneo Law student, died of serious physical injuries after three days of bloody hazing rites by the members of Aquila Legis fraternity.[1]
• June 15 – Mount Pinatubo erupts in what will be the second largest terrestrial eruption of the 20th century; the final death toll tops 800.
• June 28 – SM Megamall was opened as the 3rd SM Supermall in the Philippines.
• June 30 – The massacre of Estrellita, Carmela, and Jennifer Vizconde. Hubert Webb and the original suspects were released from prison in 2010 after they were acquitted by the Supreme Court.
• July 13 – Maureen Hultman and John Chapman were murdered by Claudio Teehankee, Jr.. The case was controversial as Teehankee is the son of a former Chief Justice.
• September 16 – The Senate of the Philippines rejects the bilateral treaty with United States which would have extended American use of Subic Bay Naval Base. American troops earlier abandoned Clark Air Base after Pinatubo erupted, and completed their withdrawal from Subic in 1992.
• October 10 – The Local Government Code is signed into law.

Thelma while nearly stationary on November 5

• November 3 – Former First Lady Imelda Marcos returns to the country to face charges against her.
• November 4–5 – Tropical Storm Uring lashes into Eastern Visayas, leaving 8,000 people dead as a result of widespread flooding in the coastal city of Ormoc, Leyte.
• November 26 – US closes and surrenders Clark Air Base.

These are TV programs that premiered and had their finales this year.

• November 24 – December 3 – Manila was selected again as a host city in the 16th Southeast Asian Games, ten years since the 11th SEA Games held in the same city in 1981. The Philippine team participated in the 16th SEA Games and placed second with 91 gold, 62 silver and 84 bronze medals for a total of 237 medals ahead of Indonesia was in the first place.

• January 14 – Kristel Moreno, actress
• February 5 – Juami Tiongson, basketball player
• February 12 – Simon Enciso, basketball player
• February 20:
  • Joshua Beloya, football player
  • Hidilyn Diaz, weightlifter
• February 21 – Jon Timmons, actor, model, and television personality
• March 15 – Bret Jackson, actor
• March 18 – Jeric Teng, basketball player
• April 1 – Franco Hernandez, member of Hashtags (d. 2017)
• April 4 – Marlon Stöckinger, racing driver
• April 13 – Gerry Mark Suerte Felipe, actor and singer
• May 3 – Bela Padilla, actress
• May 9 – Kenneth Medrano, actor and model
• May 15 – Gerald Santos, actor and singer
• May 28 – Beauty Gonzalez, actress and model
• May 29 – Vin Abrenica, actor
• June 16 – Ryan Bang, Korean actor and comedian
• June 22 – Michael Jim Polancos, comedian
• July 1 – Kim Molina, actress
• July 17 – Maverick Ahanmisi, basketball player
• August 4 – Neil Coleta, actor
• July 19 – Arny Ross, actress
• August 18 – Ed Daquioag, basketball player
• August 19 – Nathan Lopez, actor
• August 21 – Carl Bryan Cruz, basketball player
• August 25 – Marisa Park, football player
• August 26:
  • Wil Dasovich, model and vlogger
  • Haley Dasovich, model and vlogger
• September 27 – Ynna Asistio, actress
• October 4 – Nico Elorde, basketball player
• October 12 – Garrett Bolden, singer
• October 22 – Melissa Gohing, volleyball player
• October 27 – Lincoln Velasquez, vlogger
• November 13 – Kevin Alas, basketball player
• November 25:
  • Martin del Rosario, actor
  • James Forrester, basketball player
• December 4 – Phoebe Walker, actress and model
• December 11 – Mikhail Red, independent filmmaker

• April 25 – Lamberto V. Avellana, film and stage director
• May 21 – Lino Brocka, film director
• July 11 – Atang de la Rama, film actress and singer