Brandon Mayfield (born July 15, 1966) is an American attorney in Washington County, Oregon. He is best known for being erroneously linked to the 2004 Madrid train bombings. On May 6, 2004, the FBI arrested Mayfield as a material witness in connection with the Madrid attacks, and held him for over two weeks. Mayfield was never charged, and an FBI internal review later acknowledged serious errors in their investigation. Ensuing lawsuits have resulted in a formal apology from the U.S. government, a $2 million settlement, and the overturning of provisions of the USA PATRIOT Act on constitutional grounds.
Mayfield's case has been referenced in numerous scientific, political, and social journals.
Mayfield was born in Coos Bay, Oregon and grew up in Halstead, Kansas. He served in the United States Army Reserve from 1985 to 1989, and then as an officer in the Army in Bitburg, Germany from 1992 to 1994. He met his wife Mona, an Egyptian national and the daughter of a college professor, on a blind date in Olympia Washington in 1986, and converted to Islam shortly afterwards. They have lived in Beaverton, Oregon off and on since 1989. Although he was a regular worshiper at a Beaverton mosque prior to his arrest, his colleagues were unaware of his religious beliefs. The imam of the mosque has described Mayfield as "very patriotic". Mayfield has three children.