Joseph Michael Arpaio (; born June 14, 1932) is an American former law enforcement officer and politician. He served as the 36th Sheriff of Maricopa County, Arizona for 24 years, from 1993 to 2017, losing reelection to Democrat Paul Penzone in 2016.
Starting in 2005, Arpaio took an outspoken stance against illegal immigration, styling himself as "America's Toughest Sheriff". In 2010, he became a flashpoint for opposition to Arizona's SB1070 anti-illegal immigrant law, which was largely struck down by the Supreme Court of the United States. Arpaio is also known for investigating former U.S. President Barack Obama's birth certificate, and, as of 2018, he continued to claim without evidence that it was forged.
Arpaio has been accused of numerous types of police misconduct, including abuse of power, misuse of funds, failure to investigate sex crimes, criminal negligence, abuse of suspects in custody, improper clearance of cases, unlawful enforcement of immigration laws, and election law violations. A Federal court monitor was appointed to oversee his office's operations because of complaints of racial profiling. The U.S. Department of Justice concluded that Arpaio oversaw the worst pattern of racial profiling in U.S. history, and subsequently filed suit against him for unlawful discriminatory police conduct. Arpaio and the MCSO were named as defendants in dozens of civil lawsuits brought by citizens arrested by Arpaio and his deputies alleging wrongful arrest, wrongful death, entrapment and other claims, costing taxpayers in Maricopa County over $140 million in litigation against Arpaio during his tenure as sheriff.
Over the course of his career, Arpaio was the subject of several federal civil rights lawsuits. In one case he was a defendant in a decade-long suit in which a federal court issued an injunction barring him from conducting further "immigration round-ups". A federal court subsequently found that after the order was issued, Arpaio's office continued to detain "persons for further investigation without reasonable suspicion that a crime has been or is being committed." In July 2017, he was convicted of criminal contempt of court, a crime for which he was pardoned by President Donald Trump on August 25, 2017. In a separate racial-profiling case which concluded in 2013, Arpaio and his subordinates were found to have unfairly targeted Hispanics in conducting traffic stops. Though Arpaio sought another term as Sheriff in 2016, the contempt of court conviction eroded much of his remaining political support, and he was defeated in the election by Paul Penzone, a Democrat who reversed many of Arpaio's policies after taking office. Arpaio was an unsuccessful candidate in Arizona's Republican primary election for U.S. Senate in 2018.