The 2020 presidential campaign of Howie Hawkins, both the co-founder of the Green Party of the United States and thrice its gubernatorial candidate in New York, was informally launched on April 3, 2019, when Hawkins announced the formation of an exploratory committee and formally announced his campaign on May 28, 2019, to seek the Green Party nomination for the presidency of the United States in the 2020 presidential election and later the Socialist Party USA. On May 5, 2020, Hawkins announced that former Socialist Party USA vice presidential candidate Angela Nicole Walker would be his running mate. Hawkins and Walker were nominated by the Green Party on July 11, 2020.
 Hawkins also sought the nomination of the various state-based left-wing parties, including the Peace and Freedom Party, Legal Marijuana Now Party, Oregon Progressive Party, United Citizens Party, Liberty Union Party, and Vermont Progressive Party.
 In the 1980s, Hawkins joined the green movement. In 1988, Howie and Murray Bookchin founded the Left Green Network "as a radical alternative to U.S. Green liberals", based around the principles of social ecology and libertarian municipalism. In the early 1990s a press conference was held in Washington, D.C., that featured Charles Betz, Joni Whitmore, Hilda Mason, and Howie Hawkins to announce the formation of the Greens/Green Party USA. Later in December 1999, Mike Feinstein and Hawkins wrote the Plan for a Single National Green Party which was the plan to organize the ASGP and GPUSA into a single Green Party. Over the next decade he would run in multiple New York Senate and House races.
 In the 2010 New York gubernatorial election Hawkins surpassed the 50,000-vote requirement to stay on the ballot in the gubernatorial election. 
In the 2014 election, he received enough to move the Green Party line to Row D on the ballot as he had taken one-third more than the Working Families Party and twice as much as the Independence Party. In the 2018 election, Hawkins received 80,000 fewer votes than he did in his 2014 run. As a result, the party was lowered one row down to Row E, but retained ballot access.
 In 2012, Hawkins was approached over the possibility of running for the Green Party presidential nomination. He declined due to his employment commitments at UPS, which he maintained would interfere with a national campaign.
 Following his retirement from UPS, Hawkins was approached again to run by a draft movement via a public letter addressed to him. The letter was signed by former Green vice presidential nominees Cheri Honkala and Ajamu Baraka, former Green mayoral candidate and Nader's 2008 running mate Matt Gonzalez, and other prominent Green Party members.
 On April 3, 2019, Hawkins announced that he was forming an exploratory committee to prepare for a potential candidacy for the Green Party 2020 presidential nomination and formally launched his campaign on May 28, 2019, in Brooklyn, New York. On June 21, 2020, Hawkins received enough delegates to win the Green Party's presidential nomination after winning delegates from the Green Party of Michigan and Lavender Caucus. On July 11, he received the Green Party's presidential nomination with 210 delegates at the party's virtual convention.
 On October 26, 2019, Hawkins won the nomination of the Socialist Party USA as part of his effort to unite smaller left-wing parties. In November, Hawkins was endorsed by Solidarity, a U.S.-based socialist organization. On March 3, 2020, Hawkins lost the Peace and Freedom Party primary to Gloria La Riva. On August 13, 2020, he was endorsed by Socialist Alternative. Hawkins also received the nomination of the Legal Marijuana Now Party. In August 2020, Solidarity withdrew their endorsement following a poll of its members, instead taking no official position on the presidential election.
 On July 15, Hawkins sued Oklahoma over its $35,000 filing fee for president. On September 1, the Green Party of Alaska nominated Jesse Ventura for president and Cynthia McKinney for vice-president instead of Hawkins and Walker. Hawkins appeared in the ballot in thirty states.
 On May 28, 2020, the Green Party of Rhode Island announced that it would not place a presidential candidate onto the ballot for the first time since 1996 citing the danger of Donald Trump winning reelection. Hawkins later announced that he would petition as an independent candidate under the partisan label "Independent Left" in Rhode Island. However, Hawkins failed to qualify for the Rhode Island ballot after submitting only 897 valid signatures in his petition to run for office.
 A challenge was filed against Hawkins in Pennsylvania stating that the Green Party's stand-in candidates for president and vice-president had not submitted a declaration of candidacy. On September 9, Judge J. Andrew Crompton rejected a challenge to Hawkins being on the ballot in Pennsylvania although the challenge against Walker being on the ballot was accepted. Crompton ruled that Hawkins should appear on the ballot as the stand-in presidential candidate did submit a declaration of candidacy while the stand-in vice-presidential candidate had not.
 On September 10, the Pennsylvania Democratic Party appealed to the Supreme Court of Pennsylvania to remove Hawkins from the ballot. The Supreme Court of Pennsylvania ordered election officials to not print ballots until the court made a decision on whether or not Hawkins would appear on the ballot. On September 17, the Pennsylvania Supreme Court ruled five to two in favor of removing Hawkins from the ballot. All five Democratic members of the Pennsylvania Supreme Court voted to remove Hawkins while both Republican members voted to keep him on the ballot.
 Hawkins' presidential petition in Wisconsin was challenged in August under the basis that Walker had changed her residence address within South Carolina. On August 19, the staff of the Wisconsin Elections Commission recommended that Hawkins be removed from the ballot due to his petitions not having enough signatures when the signatures for the out-of-date postal address for Walker were removed. On August 20, the commission voted three to three to remove Hawkins from the ballot; all of the Democratic members of the commission voted to remove Hawkins while the Republican members voted to keep him on the ballot.
 On September 3, Hawkins filed a lawsuit to the Wisconsin Supreme Court. On September 10, the Wisconsin Supreme Court ordered election officials to stop mailing out ballots until the court ruled on whether or not Hawkins and/or Kanye West could appear on the ballot. The Wisconsin Supreme Court ruled four to three in favor of the election commission on September 14, citing that Hawkins had waited too long to file a lawsuit and that it would cause too much disruption to place his name on the ballot.
 On August 23, 2019, the Hawkins campaign announced they had met the requisite federal matching funds for California and New York. Only his campaign and that of Steve Bullock applied for primary season matching funds. On July 9, 2020, the Hawkins campaign announced they achieved federal matching fund requirements in 20 necessary states, claiming they had raised $220,000 from 4,000 donors in over 7,000 total contributions.
 Hawkins supported the Green Party's version of the Green New Deal that would serve as a transitional plan to the exclusive use of renewable energy by 2030 utilizing a carbon tax, jobs guarantee, free college, single-payer healthcare and a focus on using public programs.
 He was a critic of the Democratic version of the Green New Deal written by Alexandria Ocasio-Cortez, stating that "unfortunately, they took the brand but watered down the content".
 Hawkins disagreed with the "party-within-the-party" approach to the Democratic Party advocated by organizations such as the Democratic Socialists of America or by individuals such as Bernie Sanders. Instead, he believed that socialists should build up an independent Left party.
 Hawkins advocated for expansion of town meetings, expanding their powers to enact legislation and granting them the power to recall representatives.
 Hawkins viewed health care as a human right and a public good. His plan is to implement a single-payer National Health Insurance in which health care facilities are publicly owned, healthcare workers are salaried, and the system is governed by community boards elected by the public (two-thirds of the seats) and health care workers (one-third of the seats).
 The system would be funded by allocating current public healthcare dollars (about 70% of current spending) to the system. The rest of the funding would come from progressive taxes on individuals/families, both earned and unearned income, who earn more than 150% of the adjusted Federal Poverty Level and on large corporations.
 On October 16, 2019, a joint candidate letter called for reform in the party's primary process in response to the party's announcement that it would remove unrecognized candidates from its website list that November, an effort which the other Green candidates claimed was being to done to help Hawkins secure its nomination. This was followed by allegations of conflicts of interest among the party's leadership, who the candidates believed where helping party co-founder Hawkins, and an alleged overlooking of a violation of Green Party rules regarding Hawkins’ campaign for the Socialist Party's nomination.
 After the 2020 Green Party Nominating Convention named Hawkins as their presidential candidate, candidate Dario Hunter announced via Twitter that he would continue to pursue the presidency as an independent candidate. Hunter cited alleged irregularities and undemocratic processes throughout the Green Party presidential primary, stating that party leaders had committed “ethical lapses” to ensure Hawkins nomination, and criticizing Hawkins for what he saw as his "imperialist perspective" and "CIA talking points.”
 On February 20, 2020, Hawkins published a statement critical of his opponent in the Peace and Freedom Party nomination primary, Gloria La Riva, alleging that she supported "a 'safe strategy' of supporting Bernie Sanders in the 'battleground' states" and stating "you didn't join the Peace and Freedom Party to support Democrats." LaRiva responded stating that it was "not an honest critique" and "[f]or Hawkins to further imply that he is the stronger supporter of Peace and Freedom is not convincing." LaRiva won the Peace and Freedom Party's only primary contest in California, receiving 67% to Hawkins' 33%.