Civil Disobedience or On the Duty of Civil Disobedience by Henry David Thoreau Resistance to Civil Government, also called On the Duty of Civil Disobedience or Civil Disobedience for short, is an essay by American transcendentalist Henry David Thoreau that was first published in 1849.

In it, Thoreau argues that individuals should not permit governments to overrule or atrophy their consciences, and that they have a duty to avoid allowing such acquiescence to enable the government to make them the agents of injustice. Thoreau was motivated in part by his disgust with slavery and the Mexican–American War (1846–1848).

In 1848, Thoreau gave lectures at the Concord Lyceum entitled "The Rights and Duties of the Individual in relation to Government". This formed the basis for his essay, which was first published under the title Resistance to Civil Government in an 1849 anthology by Elizabeth Peabody called Æsthetic Papers.

The latter title distinguished Thoreau's program from that of "non-resistants" or Christian anarchists like Adin Ballou and William Lloyd Garrison, as Thoreau argued that their insistence on nonresistance as praxis against the state was grossly ineffectual. Nonetheless, Thoreau was initially inspired by the Christian anarchist ideals espoused by Ballou and Garrison.

Resistance also served as part of Thoreau's metaphor comparing the government to a machine: when the machine was producing injustice, it was the duty of conscientious citizens to be "a counter friction" (i.e., a resistance) "to stop the machine".

In 1866, four years after Thoreau's death, the essay was reprinted in a collection of Thoreau's work (A Yankee in Canada, with Anti-Slavery and Reform Papers) under the title Civil Disobedience. Today, the essay also appears under the title On the Duty of Civil Disobedience, perhaps to contrast it with William Paley's Of the Duty of Civil Obedience to which Thoreau was in part responding.

For instance, the 1960 New American Library Signet Classics edition of Walden included a version with this title. On Civil Disobedience is another common title.