Age of candidacy is the minimum age at which a person can legally qualify to hold certain elected government offices. In many cases, it also determines the age at which a person may be eligible to stand for an election or be granted ballot access.

The first known example of a law enforcing age of candidacy was the Lex Villia Annalis, a Roman law enacted in 180 BCE which set the minimum ages for senatorial magistrates.

Many youth rights groups view current age of candidacy requirements as unjustified age discrimination. Occasionally people who are younger than the minimum age will run for an office in protest of the requirement or because they don't know that the requirement exists. On extremely rare occasions, young people have been elected to offices they do not qualify for and have been deemed ineligible to assume the office.

In 1934, Rush Holt of West Virginia was elected to the Senate of the United States at the age of 29. Since the U.S. Constitution requires senators to be at least 30, Holt was forced to wait until his 30th birthday, six months after the start of the session, before being sworn in.

James Richard "Rick" Perry (born March 4, 1950) is the 47th and current Governor of Texas. Perry, a Republican, was elected Lieutenant Governor of Texas in 1998 and assumed the governorship in December 2000 when then-governor George W. Bush resigned to become President of the United States. Perry was elected to full gubernatorial terms in 2002, 2006 and 2010. With a tenure in office to date of &1000000000000001100000011 years, &10000000000000188000000188 days, Perry is the longest continuously serving current U.S. governor, and the second longest serving current U.S. governor—after Terry Branstad of Iowa. Perry served as Chairman of the Republican Governors Association in 2008 (succeeding Sonny Perdue of Georgia) and again in 2011. Perry is the longest serving governor in Texas state history. As a result, he is the only governor in modern Texas history to have appointed at least one person to every eligible state office, board, or commission position (as well as to several elected offices to which the governor can appoint someone to fill an unexpired term, such as six of the nine current members of the Texas Supreme Court).

Ronald Ernest "Ron" Paul (born August 20, 1935) is an American politician who has been the U.S. Representative for Texas's 14th congressional district, which includes Galveston, since 1997, and a three-time candidate for President of the United States, as a Libertarian in 1988 and as a Republican in 2008 and currently 2012. He is an outspoken critic of American foreign and monetary policies, including the Military–industrial complex and the Federal Reserve, and is known for his libertarian-leaning views, often differing from his own party on certain issues.

A native of Pittsburgh, Pennsylvania, Paul is a graduate of Gettysburg College and Duke University School of Medicine, where he earned his medical degree. He served as a medical officer in the United States Air Force from 1963 until 1968. He worked as an obstetrician-gynecologist from the 1960s to the 1980s, delivering more than 4,000 babies. He became the first Representative in history to serve concurrently with a child in the Senate when his son Rand Paul was elected to the United States Senate for Kentucky in 2010.

Ronald Wilson Reagan ( /ˈrɒnəld ˈwɪlsən ˈreɪɡən/; February 6, 1911 – June 5, 2004) was the 40th President of the United States, serving from 1981 to 1989. Prior to that, he was the 33rd Governor of California from 1967 to 1975 and a radio, film and television actor.

Born in Tampico, Illinois and raised in Dixon, Reagan was educated at Eureka College, earning a Bachelor of Arts degree in economics and sociology. After his graduation, Reagan moved first to Iowa to work as a radio broadcaster and then in to Los Angeles in 1937 where he began a career as an actor, first in films and later television. Some of his most notable films include Knute Rockne, All American, Kings Row, and Bedtime for Bonzo. Reagan served as president of the Screen Actors Guild, and later as a spokesman for General Electric (GE); his start in politics occurred during his work for GE. Originally a member of the Democratic Party, his positions began shifting rightward in the late 1950s, and he switched to the Republican Party in 1962. After delivering a rousing speech in support of Barry Goldwater's presidential candidacy in 1964, he was persuaded to seek the California governorship, winning two years later and again in 1970. He was defeated in his run for the Republican presidential nomination in 1968 as well as 1976, but won both the nomination and general election in 1980, defeating incumbent Jimmy Carter.