Thomas Edward Perez was born in Buffalo, New York, in 1961, to parents who were immigrants from the Dominican Republic. He graduated from Brown University in 1983 and then received a law degree and a master's in public policy from Harvard University in 1987. Perez worked his way through college and graduate school before embarking on a career in public service.

He began working for the U.S. Department of Justice in 1989 as a federal prosecutor and a civil rights lawyer. From 1995 to 1998, Perez served as special counsel to Senator Edward Kennedy. He then headed up the civil rights division at the Department of Health and Human Services. In 2002, he won a seat on the city council in Montgomery, Maryland, and served until 2006 when he was appointed secretary of the Maryland Department of Labor, Licensing, and Regulation.

In 2009, President Barack Obama nominated Perez to serve as assistant Attorney General of Civil Rights in the Department of Justice. In that position, Perez fought against voter identification laws and worked to enforce laws that protected against discrimination. He also gained a reputation as a supporter of organized labor and immigrant rights. When he was nominated as secretary of the Department of Labor in 2013, many Republicans expressed concern about his appointment. Although President Obama nominated him in March 2013, Perez's confirmation did not take place until July 2013.