Mary Grace Natividad Sonora Poe-Llamanzares (born September 3, 1968) is a Filipino politician who served as a senator of the Philippines from 2013 to 2025. An independent, she previously served as the chairperson of the Movie and Television Review and Classification Board (MTRCB) from 2010 to 2012. She was a candidate in the 2016 Philippine presidential election, having run as the standard-bearer of the Partido Galing at Puso (PGP).

The adoptive daughter of actors Fernando Poe Jr. and Susan Roces, she studied at the University of the Philippines Manila before moving to Boston College in the United States, where she finished a degree in political science. Having stayed in the United States for her adult life, she returned to the Philippines in 2004 to help her father campaign in his bid for the Philippine presidency. After he died later that year, Poe remained in the Philippines began pursuing her father's rights over the results of the election and campaigned against alleged electoral fraud.

Poe ran for a seat in the Philippine Senate during the election in 2013 as an independent affiliated with the Team PNoy coalition of Benigno Aquino III. She ended up winning more votes than other candidates and over 20 million votes, ahead of Loren Legarda, who previously topped two elections. She was a candidate for the 2016 presidential election. Despite numerous attempts to have her disqualified based on questions regarding her citizenship, the Supreme Court of the Philippines deemed her a natural-born Filipino citizen and she was qualified to become president based on her 10-year residency. Poe placed third in the presidential race count. In May 2019, Poe was reelected as senator, with over 22 million votes.

Poe was found on September 3, 1968, in Iloilo City by a woman, in the holy water font of Jaro Metropolitan Cathedral, the main church of the city.

When the infant was discovered, the parish priest named her "Grace" in the belief that her finding was through divine grace; she was christened by Jaime Sin, the Archbishop of Jaro, who would later become Archbishop of Manila. Although the cathedral issued an announcement in the hopes that her biological mother would claim her, no one stepped forward.

Poe was eventually taken in by the Militar family, with Sayong Militar's in-law Edgardo, who was a signatory on the child's foundling certificate, considered to be her possible father. Her name on her original Certificate of Live Birth was given as Mary Grace Natividad Sonora Militar. Sayong Militar later passed Grace on to her friend Tessie Ledesma Valencia, an unmarried, childless heiress of a sugar baron from Bacolod, Negros Occidental.

Valencia was also a friend of film stars Fernando Poe Jr. and Susan Roces, who were newlyweds at the time; Valencia was an acquaintance of Roces and was the one who brought Grace in trips between Bacolod and Manila. The Poes took Grace in after Valencia decided the baby would be better off with two parents in the Philippines rather than with her as a single parent in the United States, where she was moving to. Militar was initially hesitant in letting the Poe couple adopt Grace because she was unfamiliar with them, having entrusted the baby to Valencia, but was convinced by Archbishop Sin to let the couple adopt her.

Poe was legally adopted by the actors Fernando Poe Jr. and Susan Roces and she was named Mary Grace Natividad Sonora Poe by them. While still young, she watched her father from the sets of his movies—even playing minor roles in some of them, such as the daughter of Paquito Diaz's character in Durugin si Totoy Bato, and as a street child in Dugo ng Bayan. Ultimately, Poe did not enter show business.