The Green Party is one of the political parties in the United States, and similar in mission to many of the worldwide Green Parties. The Greens have been active as a third party since 2001. The party first gained widespread public attention during Ralph Nader's presidential runs in 1996 and 2000. Currently, the primary national Green Party organization in the U.S. is the Green Party of the United States, which has eclipsed the earlier Greens/Green Party USA.
The Green Party in the United States has won elected office mostly at the local level; most winners of public office in the United States who are considered Greens have won nonpartisan-ballot elections (that is, the winning Greens won offices in elections in which candidates were not identified on the ballot as affiliated with any political party). The highest-ranking Greens ever elected in the nation were Richard Carroll  who is a member of the Arkansas House of Representatives elected in 2008, John Eder who was a member of the Maine House of Representatives 2002-2006, and Audie Bock, who was elected to the California State Assembly in 1999 but switched her registration to Independent seven months later running as an independent in the 2000 election. In 2005, the Party had 305,000 registered members in states that allow party registration, as well as tens of thousands of members and contributors in the rest of the country. During the 2006 elections the party had ballot access in 31 states.
- Green Party members holding elected office in the United States Green Party of California, June 2007
- Sole Green Party Legislator Makes Switch RAND California Policy Bulletin, Oct. 18, 1999
- Ca 2000 Election Night Returns (PDF) The Capital Connection, Nov. 08, 2000
- Green Party Ballot Status and Voter Registration Totals (United States) Green Party of California, May 2005
- Greens Win Ballot Access in 31 States, Up From 17 in January Green Party of the United States, Sep. 05, 2006