- Students for a Democratic Society (SDS):
- The American Civil Liberties Union (ACLU):
- The National Association for the Advancement of Colored People (NAACP):
- The United Auto Workers (UAW):
- The American Friends Service Committee (AFSC):
- The Women's Strike for Peace:
- The Clergy and Laity Concerned about Vietnam:
- The Vietnam Veterans Against the War:
- The War Resisters League (WRL):
- The Black Panther Party (BPP):
- The Young Socialist Alliance (YSA):
- The Communist Party of the United States of America (CPUSA):
And many more.
These organizations expressed their opposition to the Vietnam War through various forms of activism, such as protests, demonstrations, civil disobedience, and political lobbying. They played a significant role in building public support for the anti-war movement and in pressuring the US government to end its involvement in the war.