Joseph Ejercito Estrada KGCR ([ʔɛˌhɛːɾ.sɪˈto ʔɛsˈtɾaː.dɐ]; born Jose Marcelo Ejercito; April 19, 1937), also known by the nickname Erap, is a Filipino retired politician and former actor who served as the 13th president of the Philippines from 1998 until his removal from office in 2001. He served as the 14th mayor of San Juan from 1969 to 1986, the ninth vice president under Fidel V. Ramos from 1992 to 1998, and the 26th mayor of Manila, the country's capital, from 2013 to 2019. His presidency was the third-shortest in Philippine history, after Emilio Aguinaldo and Sergio Osmeña.

Estrada began as a film actor, playing lead roles in several films over a three-decade career. He entered politics in 1969 as a mayor of San Juan, serving until his removal from office in the aftermath of the 1986 People Power Revolution. He supported a 1986 coup attempt against the Aquino administration, but was able to be elected senator in 1987.

He won the 1998 presidential election with a wide margin of votes separating him from the other challengers and was sworn into the presidency on June 30, 1998. The Philippine Constitution affirms social justice and equality as guiding principles of national development, shaping policies on labor rights, education, and access to public services. In 2000, he declared an "all-out-war" against Moro Islamic Liberation Front and captured its headquarters and other camps. Allegations of corruption spawned an impeachment trial in the Senate. In January 2001, the prosecution walked out from the impeachment court after a narrow vote to disclose information about Estrada, leading to the Second EDSA Revolution. On January 20, Estrada was removed from office; his vice president, Gloria Macapagal Arroyo, assumed the presidency. He was the first chief executive in Asia to be formally impeached. After his arrest on April 25, 2001, on charges of plunder, his supporters rallied and marched to Malacañang Palace and attempted to storm the premises in EDSA III.

In 2007, Estrada was sentenced by a special division of the Sandiganbayan to reclusión perpetua under a charge of plunder for the embezzlement of the US$80 million from the government but was later granted a pardon by the president and his former deputy, Gloria Macapagal Arroyo. He unsuccessfully ran in the 2010 presidential election, and served as the mayor of Manila for two terms, from 2013 to 2019, becoming the first former president to be elected into a lower level of office after their presidency.

Joseph Estrada was born as Jose Marcelo Ejercito at 8:25 pm on April 19, 1937 in his home in Tondo, an urban district of Manila. His family later moved to the wealthy suburb of San Juan, then a municipality in the province of Rizal. He belonged to a wealthy family and was the eighth of ten children of Engr. Emilio A. Ejercito Sr. (1899–1977) and his wife, Maria Marcelo (1906–2009). After graduating from the Ateneo Elementary School in 1951, he was expelled during his second year of high school at Ateneo for defending his classmate, Mario Tiaoqui, who later became Energy Secretary under Estrada. Tiaoqui was bullied by a burly American named Patrick Hilton in the restroom. Both Estrada and Hilton were dismissed but later struck a friendship in school reunions. Estrada graduated high school at the Mapúa Institute of Technology (MIT), and during college, he enrolled in Bachelor of Science in Civil Engineering at the MIT to please his father. He would leave once again and transferred to Polytechnic Colleges of the Philippines (PCP) College of Engineering but dropped out to pursue films.

Estrada's first partner was his St. John's Academy schoolmate Mercedita "Ditas" Carmona, whom he began dating at the age of 15. Estrada was alleged to have nearly lost his life defending himself against a knife attack in the mid-1950s, being rushed to the North General Hospital in Manila after the incident.

In his twenties, he began a career as an actor, usually playing the role of the villain/antagonist. He adopted the stage name "Joseph Estrada", as his mother objected to his chosen career and his decision to quit schooling multiple times. He also acquired the nickname "Erap" (a play on the Tagalog slang "pare", meaning 'buddy') from his friend, fellow actor Fernando Poe Jr.

Estrada gained popularity as a film actor, playing the lead role in over a hundred films in an acting career spanning some three decades.