Orestes Augustus Brownson (1803-1876) was a New England intellectual and activist, preacher and labor organizer. Brownson is best remembered for his affiliation with the New England Transcendentalists.

Brownson was born to poor farmers in Stockbridge, Vermont, and educated himself. He had a series of religious conversions throughout his life. In 1822 Brownson became a Presbyterian and in 1824 he became a Universalist, becoming ordained in 1826 and preaching in New York and New England. Later, rejecting Universalism, he became associated with Robert Dale Owen and Fanny Wright in New York City and organized the Workingmen's Party. Then he became a Unitarian, preaching in Walpole, New Hampshire from 1832 and in Canton, Massachusetts from 1834.

For the next decade, Brownson was a part of the Transcendentalist movement which swept through the Boston Unitarian community. He read in English Romanticism and English and French reports on German Idealist philosophy, and was most passionate about the work of Victor Cousin. In 1836, the year of Emerson's Nature, Brownson participated in the founding of the Transcendental Club; he also published a pamphlet, New Views of Christianity, Society, and the Church, which combined Transcendental religious views with radical social egalitarianism, angrily criticizing the unequal social distribution of wealth as un-Christian and unprincipled. He founded a magazine, The Boston Quarterly Review, in 1838, and wrote political, intellectual, and religious essays.

In 1844 Brownson converted again, to Catholicism, his religion for the rest of his life; his reputation among the Transcendentalists fell, as did his opinion of them. As a Catholic, Brownson became politically conservative. He repudiated his earlier Fourierist and Owenite ideas, now criticizing socialism and utopianism as vigorously as he had once promoted them. In 1857 he wrote a memoir, The Convert; or, Leaves from My Experience.