Thomas John Perrelli (born March 12, 1966) is an American lawyer and the former United States associate attorney general.

Before joining the Obama administration, Perelli was managing partner of Jenner & Block's Washington office, co-chair of the firm's Entertainment and New Media Practice, and a member of the firm's Appellate and Supreme Court, Class Action Litigation, Health Care Law, Intellectual Property, Litigation & Dispute Resolution, Media and First Amendment, and Telecommunications Practices.

[citation needed] Since his return to Jenner and Block in 2001, Perrelli has also represented Democratic voters and elected officials in redistricting litigation arising out of the 2000 census.

[citation needed] In 1997, Perrelli left Jenner & Block to join the Department of Justice and served as counsel to Attorney General Janet Reno.

In that role, Perrelli led a staff of 100 attorneys charged with defending the constitutionality of federal statutes, defending federal agency action and regulations, representing the diplomatic and national security interests of the United States in courts of law, and conducting significant Title VII, personnel and social security litigation.

In addition, he played a leading role on significant policy issues ranging from medical records privacy and the use of adjusted figures in the census to Indian gaming and legal ethics.