Brigitte Gabriel, born Hanan Qahwaji on October 21, 1964, in Marjeyoun, Lebanon, is a Lebanese-American conservative activist, author, lecturer, and speaker, and the founder and president of ACT for America (also styled as ACT! for America), a prominent anti-Muslim advocacy organization. Raised in a Maronite Christian family in southern Lebanon, she experienced the Lebanese Civil War firsthand, during which her home was destroyed by Muslim militias in 1975, forcing her family to live in a bomb shelter for seven years. This trauma, along with surviving Israeli invasions, profoundly shaped her worldview and advocacy against Islam and Islamist extremism. After fleeing to Israel in 1984 (living there until 1989), she worked in media and studied business administration, beginning her career as a news anchor under the pseudonym Nour Semaan for Middle East Television (METV), covering events in multiple languages including Arabic, Hebrew, French, and English. In 1989, she immigrated to the United States, initially settling in Washington, D.C., and adopted the name Brigitte Gabriel.

ACT for America, founded in 2007, is the largest grassroots anti-Muslim advocacy organization in the U.S., focusing on countering radical Islam and Islamist extremism, promoting national security awareness, opposing Muslim immigration and Sharia law, lobbying against Islamic influences, and countering Islamist influence. Labeled the 'NRA of national security,' it promotes policies against what she perceives as radical Islam's threat to Western values. Under her leadership, ACT for America has grown into a multimillion-dollar nonprofit with over 750,000 members and chapters in all 50 U.S. states, financially supported by major donors like Nina Rosenwald and the Donors Capital Fund. The organization has been criticized by groups like the Southern Poverty Law Center (SPLC) as an anti-Muslim hate group and labeled by critics as Islamophobic for promoting conspiracy theories and inflammatory rhetoric.

Gabriel is a prolific author of bestselling books including 'Because They Hate: A Survivor of Islamic Terror Warns America' (2006), 'They Must Be Stopped: Why We Must Defeat Radical Islam and How We Can Do It' (2008), and 'Rise: In Defense of Judeo-Christian Values and Freedom' (2021), which have become staples in conservative circles. She is a prominent conservative speaker on radical Islam, frequently appearing on media outlets like Fox News, and her lectures often draw controversy for strong anti-Islam rhetoric. Her activism includes lobbying the U.S. House Committee on Homeland Security, consulting for foreign entities like Israel, and affiliations with conservative institutions like the Heritage Foundation and Family Research Council. She endorsed Donald Trump in 2016 and has been awarded by groups like the Christian Coalition. Gabriel collaborates with fellow anti-Islam activists including Walid Shoebat and Pamela Geller through the American Freedom Defense Initiative.

She faces ongoing controversies, including accusations of hate speech from the Council on American-Islamic Relations (CAIR), which she has attacked as a terrorist front, and legal representation in defamation suits related to her advocacy. Critics, including the SPLC, have condemned her for inflammatory statements, such as claiming that Muslims pose an existential threat to Western civilization, leading to allegations of fostering division and extremism. Despite this, she maintains significant influence in conservative networks opposing Muslim immigration and Sharia law in the West. Her personal life remains relatively private, though she is married to Robert Gabriel.