Gary Earl Johnson is an American businessman and politician who served as the 29th governor of New Mexico from 1995 to 2003 as a member of the Republican Party. He has been a member of the Libertarian Party since 2011 and was the party's nominee for President of the United States in the 2012 and 2016 elections. He was also the Libertarian nominee in the 2018 U.S. Senate election in New Mexico.

The 2012 presidential campaign of Gary Johnson, the 29th governor of New Mexico, was announced on April 21, 2011. He declared his candidacy for the 2012 Republican Party nomination for President of the United States. On December 28, 2011, Johnson withdrew his candidacy for the Republican nomination, and declared his candidacy for the 2012 presidential nomination of the Libertarian Party. The 2012 Libertarian National Convention was held during the first weekend of May 2012. On May 5, 2012, after promoting his libertarian-oriented political positions to delegates, Johnson received the most votes at the convention and became the official 2012 Libertarian presidential nominee. On November 6, 2012, Johnson received just under 1% of the popular vote in the general election, amounting to more than 1.2 million votes, more than double what the Barr/Root ticket received in 2008. This was the most successful result for a third-party presidential candidacy since 2000, and the best in the Libertarian Party's history by vote number at the time. Johnson ran again in 2016 and received nearly four times his 2012 vote total.