This is a list of political parties in the United States, both past and present. The list does not include independents. Not all states allow the public to access voter registration data. Therefore, voter registration data should not be taken as the correct value and should be viewed as an underestimate.

Active parties

Major parties

Third parties

Represented in state legislatures

The following third parties have members in state legislatures affiliated with them.

Ballot access in multiple states

Ballot access in a single state

Other parties with ballot access

The following third parties have ballot access in at least one state and are not represented in a national office or state legislature.

Multi-state

Single-state

Active parties without ballot access

''The following parties have been active in the past 4 years, but as of December 2021, did not have official ballot access in any state. ''

Multi-state

Single-state

Major parties in Puerto Rico

The following parties are represented in the Puerto Rican Legislature.

Historical parties

Held national office or elected to Congress

Multi-state political parties

Single-state political parties

Political parties in the unincorporated territories

Non-electoral organizations

Active

These organizations generally do not nominate candidates for election, but some of them have in the past; they otherwise function similarly to political parties.

Historical

These historical organizations did not officially nominate candidates for election but may have endorsed or supported campaigns; they otherwise functioned similarly to political parties.

Party registration

Officially recognized parties in states are not guaranteed have ballot access, membership numbers of some parties with ballot access are not tracked, and vice versa. Not all of these parties are active, and not all states record voter registration by party. Boxes in gray mean that the specific party's registration is not reported.

Parties by number of registered voters