The Poetry Foundation is a United States literary society that seeks to promote poetry and lyricism in the wider culture. It was formed from Poetry magazine, which it continues to publish, with a 2003 gift of $200 million from philanthropist Ruth Lilly.

Its mission, which was updated in 2022, is "to amplify poetry and celebrate poets by fostering spaces for all to create, experience, and share poetry." In partial furtherance of this objective, the foundation runs a blog called Harriet. Poets who have blogged at Harriet on behalf of The Poetry Foundation include Christian Bök, Stephanie Burt, Wanda Coleman, Kwame Dawes, Linh Dinh, Camille Dungy, Annie Finch, Forrest Gander, Rigoberto González, Cathy Park Hong, Bhanu Kapil, Ange Mlinko, Eileen Myles, Craig Santos Perez, A. E. Stallings, Edwin Torres, and Patricia Smith. In addition, the foundation provides several awards for poets and poetry. It also hosts free workshops, readings, exhibitions, and is home to a 30,000-volume poetry library.

The Poetry Foundation is a non-profit, charitable, 501(c)(3) organization.

The foundation is the successor to the Modern Poetry Association (previous publisher of Poetry magazine), which was founded in 1941. The magazine, itself, was established in 1912 by Harriet Monroe. Monroe was its first publisher and editor until her death in 1936. The Poetry Foundation is one of the largest literary foundations in the world.

In 2003, Poetry magazine received a bequest from the estate of Ruth Lilly originally said to be worth over $100 million, but which grew to be about $200 million when it was given out.

The magazine learned in 2001 that it would be receiving the bequest. Before announcing the gift, the magazine waited a year and reconfigured its governing board, which had been concerned with fundraising. The foundation was created, and Joseph Parisi, who had been editor of the magazine for two decades, volunteered to head the new organization. Christian Wiman succeeded to the editorship in 2003. Parisi resigned from the foundation after a few months.

The new board used a recruiting agency to find John Barr, a former executive and published poet, to head the foundation. Robert Polito, the poet and critic who founded and directed the graduate writing program at the New School, succeeded Barr in 2013 and served until 2015. In December, 2015, Henry S. Bienen, President Emeritus of Northwestern University was named president. Bienen served as the president of the Poetry Foundation from December 2015 until his resignation on June 10, 2020, following criticism of the foundation's support for marginalized artists. In April 2021, the foundation named former Chicago commissioner for cultural affairs, Michelle T. Boone, as its new president.

Part of the Lilly bequest was used to build the Poetry Foundation's building in Near North Side, Chicago. The building, designed by John Ronan, opened in 2011. It houses a poetry library, reading spaces, and free events, all open to the public, and provides office and editorial space for the Poetry Foundation and Poetry magazine staff.