Tides Foundation is a left-leaning donor advised fund based in the United States that manages over $1.4 billion in assets.

[7] Tides was founded in 1976 by Drummond Pike, who worked with Jane Bagley Lehman, heir to the R. J. Reynolds Tobacco Company fortune.

[8]: 265 [9] In the chapter entitled "The Givers" in his 2017 publication by the same name, The Givers: Wealth, Power, and Philanthropy in a New Gilded Age, which is a more recent edition of his 2010 book, Fortunes of Change: The Rise of the Liberal Rich and the Remaking of America, David Callahan wrote that Pike was an "entrepreneurial activist" and that Pike and his "wealthy friends" teamed up" to create Tides which "used donor-advised funds to direct resources to progressive causes.

[11] Tides was conceived as a nationally oriented community foundation, and founded out of Pike's frustration with established philanthropy's perceived neglect of progressive issues.

[16] Tides Canada, which is based in Vancouver, makes grants through its foundation and has a charity that supports environmental and social justice projects.

[21] Organizations that began as projects of Tides include Campaign to Defend the Constitution, Higher Education Recruitment Consortium, People for the American Way, Pew Internet and American Life Project, Rockridge Institute, Social Venture Network, Urgent Action Fund, and V-Day.

The CEO of Tides, Melissa L. Bradley, stated in a blog post in October 2011 that the movement "represents the best of American ideals and ingenuity.

"[30] In 2023, the Washington Examiner, a U.S. conservative news outlet, reported that the Tides Foundation and its affiliate, the Tides Center, had donated over $1 million to anti-Israel groups behind demonstrations pushing for an Israel-Gaza conflict ceasefire and downplaying Palestinian terror in the Middle East.

Black Lives Matter and Tides had been partners, with the former acting as the fiscal sponsor for the latter while the organization awaited its tax-exempt status.