This is a list of statewide public opinion polls that have been conducted relating to the Democratic primaries for the 2020 United States presidential election. The persons named in the polls are declared candidates or have received media speculation about their possible candidacy.

Given the large number of potential candidates, the scores of certain low-polling and infrequently-polled candidates have been combined within the "other" column; their exact scores may be viewed by viewing the footnotes associated with each poll. The polls included are among Democrats or Democrats and Democratic-leaning independents, and do not include Republican-leaning independents. The statewide polls are ordered by the scheduled date of the state's primary or caucus. Open-ended polls are included and marked with an asterisk (*), but closed-ended versions of such polls are listed where possible. If multiple versions of polls are provided, the version used for debate qualification is prioritized, then the version among likely voters, then registered voters, then adults.

The Democratic National Committee has determined that candidates may qualify for the first two Democratic primary debates either by polling at 1% or higher in at least three national or early-state (Iowa, New Hampshire, Nevada, and South Carolina) polls sponsored or conducted by designated organizations (in different regions if by the same organization) published after January 1, 2019 up until June 12, 2019, or by a fundraising threshold requiring at least 65,000 unique donors with at least 200 in 20 different states. Should more than 20 candidates meet either threshold, then candidates meeting both thresholds will be given highest priority for entry into the debates, followed by those with the highest polling average and those with the most donors. The pollsters and sponsors of polls designated for consideration by the DNC are the Associated Press, ABC News, CBS News, CNN, The Des Moines Register, Fox News, the Las Vegas Review-Journal, Monmouth University, NBC News, The New York Times, National Public Radio, Quinnipiac University, Reuters, the University of New Hampshire, USA Today, The Wall Street Journal, The Washington Post, and Winthrop University.^[1] Open-ended polls do not count towards the polling threshold.^[2]

For the third and fourth primary debates, candidates will be required to meet both polling and fundraising thresholds, with the prior considering only polls between June 28 and August 28, 2019 and increased to 4 qualifying polls at 2% support, now excluding surveys sponsored by the Las Vegas Review-Journal and Reuters; the latter requirement has also been increased, to 130,000 unique donors with at least 400 in 20 different states.^[3]

Individuals who have been included in national Democratic primary polls but have either ruled out their candidacy or not expressed interest in running include Stacey Abrams, Michael Avenatti, Sherrod Brown, Hillary Clinton, Mark Cuban, Andrew Cuomo, Al Franken, Eric Garcetti, Tim Kaine, Jason Kander, Joe Kennedy III, John Kerry, Mitch Landrieu, Terry McAuliffe, Chris Murphy, Gavin Newsom, Michelle Obama, Howard Schultz, Oprah Winfrey, and Mark Zuckerberg.

The following Morning Consult^[4] weekly poll archive^[5][6][7] graph depicts the evolution of the standing of each candidate in the early primary states (Iowa, New Hampshire, Nevada and South Carolina) since February 2019.

Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.

The following Morning Consult^{[8][9][10][11][12][13][14][15]} graph depicts the evolution of the standing of each candidate in the March 3, 2020 Super Tuesday states (Alabama, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont, and Virginia) since January 7, 2020.

Graphs are unavailable due to technical issues. There is more info on Phabricator and on MediaWiki.org.

The following dates reflect either the confirmed or expected dates of Democratic primaries and caucuses in 2020. Those for contests in U.S. territories with no date yet set are based on dates estimated by The Green Papers based on past years. The pledged delegate numbers listed below are based on the presidential votes in 2008, 2012, and 2016, as well as the number of electoral votes of each state in 2020. The number of DNC members and distinguished party leaders in the count of unpledged PLEO (party leaders and elected officials) delegates is based on the 2016 Democratic National Convention, while the number of unpledged officeholders (governors, members of Congress, and their equivalents in non-state jurisdictions) reflects their current total. The numbers of pledged delegates do not yet account for delegate bonuses or penalties from timing or clustering.^[16][17][18]

States listed with a lavender background and an asterisk (*) do not yet have a date set by existing statute. States with a light yellow background and a dagger (†) are set to shift their primary or caucus date following the expected passage of legislation moving the dates of their contests. If not already listed as such, the date to which the contest is expected to be moved is listed in parentheses. Party-run primaries (also described as either a firehouse primary or caucus in some jurisdictions) are listed with two asterisks (**).^[16][17][18]

The Iowa Democratic caucus was held on February 3, 2020.^[18]

The results of a final poll from The Des Moines Register were not released as scheduled on February 1, after an interviewee complained that Pete Buttigieg was not given as a poll option during their interview, with the omission reportedly attributed to human error. As the polling firm was unable to determine whether the mistake was an isolated incident or not, pollster Ann Selzer decided to withhold the results of the poll altogether, marking the first time in 76 years that the final pre-caucus poll was not released by the Register.^[19][20] The poll was later leaked on Twitter, with results confirmed by FiveThirtyEight showing Sanders in the lead with 22%, followed by Warren with 18%, Buttigieg with 16% and Biden with 13%.^[21]

The New Hampshire Democratic primary was held on February 11, 2020.^[18]

The Nevada Democratic caucus was held on February 22, 2020.^[18]

The South Carolina Democratic primary was held on February 29, 2020.^[18]

The Alabama Democratic primary was held on March 3, 2020.^[18]

The Arkansas Democratic primary was held on March 3, 2020.^[18]