Charles Eugene "Chip" Roy (born August 7, 1972) is an American attorney and politician serving as the U.S. representative for Texas's 21st congressional district. A member of the Republican Party, Roy took office on January 3, 2019. Before his election to Congress, he served as chief of staff to Senator Ted Cruz and as first assistant attorney general of Texas. A member of and policy chair of the House Freedom Caucus, Roy is considered a member of the most conservative faction of the House Republican Conference.

Roy was born in Bethesda, Maryland, and raised in Lovettsville, Virginia. His parents, Don and Rhonda Roy, were conservatives who supported Ronald Reagan and helped shape Roy's political views.

After graduating from Loudoun Valley High School, Roy attended the University of Virginia, receiving a Bachelor of Science in commerce in 1994 and a Master of Science in information systems in 1995. There, he worked as a dorm resident assistant for a year. After graduation Roy spent three years as an investment banking analyst, after which he decided to pursue a different career. He enrolled at the University of Texas School of Law, where he met his future wife, Carrah. He graduated in 2003 with a Juris Doctor.

Though initially Roy saw politics "as an avocation, a sort of interest, but not something I would do anytime soon, if ever", his mind began to change when, while still in law school, he began working for then-Texas attorney general John Cornyn on his 2002 campaign for the United States Senate. After the September 11 attacks, Roy reflected on his goals. "I was in law school when September 11 happened. I will always remember that moment, crystallized in my head. That had a lot to do with my commitment to public service", he has said. When Cornyn was elected and made vice chairman of the Republican Committee and the Judiciary Committee, Roy served as his staff director and senior counsel. Roy provided counsel for Cornyn and his staff on legislative issues including nominations, intellectual property, crime, civil justice reform and advising him during the immigration reform debates under the George W. Bush administration. Roy worked for Cornyn until 2009.

Roy returned to Texas as a special assistant in the office of the United States attorney for the Eastern District of Texas. In 2006, Roy met Ted Cruz, then Texas solicitor general, during a strategy session discussing the case League of United Latin American Citizens v. Perry, a case about redistricting that Cruz argued before the United States Supreme Court.

Roy resigned from his job as a special assistant U.S. attorney after six months to be a ghostwriter on then-Governor of Texas Rick Perry's 2010 book Fed Up! and work for Perry's 2012 presidential campaign. The book served as a campaign agenda for Perry's campaign, and offered a range of Perry's positions, including criticism of the Social Security system as unconstitutional (calling it "a Ponzi scheme"), changing the election of U.S. senators back to state legislatures (they were made popularly elected by the Seventeenth Amendment), ending life tenure for federal judges, and repealing the 16th Amendment (which allows a federal income tax). The book also denounces as "overreach" federal efforts to regulate health care, labor conditions, energy policy, and pollution. In the book's acknowledgments section, Perry singled out Roy for "special recognition" for resigning his previous post "to devote himself full-time to the completion of the original manuscript" and his "amazing knowledge of the U.S. Constitution and other Founding documents, and a keen ability to frame federalist arguments in striking terms that make complicated law easier for non-lawyers like me to understand and discuss." In his review of the book, Gene Healy of the libertarian Cato Institute credited Roy as "the guy who did most of the heavy lifting in the book."

On April 1, 2011, Perry announced Roy as his choice for Texas's director of state-federal relations, an office whose duties include lobbying for federal funds for state institutions (such as grants to universities).

During the confirmation hearings for his position before the Texas Senate, Roy said he would oppose an "intrusive federal government that spends our money recklessly." He promised to help Texas legislators "push back on Washington where necessary" and stand up for "liberty, state sovereignty and an end to the crippling pile of debt and regulation coming from Washington that is destroying our nation and endangering the state." When asked about the recent Texas House vote to slash most of the office's funds, transferring them to a tuition reimbursement program for children of the military, he said it was "hardly surprising…I might have voted to cut it as well, based on what I understand of the office, but possibly without hiding behind the political gamesmanship of moving it from one account to another." He promised to consider eliminating the entire office if it didn't "stand for something." Roy's nomination was opposed by Texas state senator Kirk Watson, who pointed out that the office's mission was "to promote communication and build relationships between the state and federal governments" and asked Roy "when you or someone else" decided to redefine its purpose. The committee approved Roy's nomination, 6–1, with the full State Senate later confirming the nomination. Roy served in the office from April to October 2011.