Burke's political career began in 1765 when he became private secretary to the marquess of Rockingham, then prime minister, and formed a lifelong friendship with that leader. He also entered Parliament in 1765 and there strove for a wiser treatment of the American colonies. In 1766 he spoke in favor of the repeal of the Stamp Act, although he also supported the Declaratory Act, asserting Britain's constitutional right to tax the colonists. In his famous later speeches on American taxation (1774) and on conciliation with the colonies (1775), he did not abandon that position; rather he urged the imprudence of exercising such theoretical rights.

At a time when political allegiances were based largely on family connections and patronage and political opposition was generally regarded as factionalism, Burke, in his Thoughts on the Cause of the Present Discontents (1770), became the first political philosopher to argue the value of political parties. He called for a limitation of crown patronage (so-called economical reform) and as paymaster of the forces (1782-83) in the second Rockingham ministry was able to enact some of his proposals.

He was also interested in reform of the East India Company and drafted the East India Bill presented (1783) by Charles James Fox. Influenced by Sir Philip Francis, he instigated the impeachment and long trial of Warren Hastings. Hastings was acquitted, but Burke's speeches created some new awareness of the responsibilities of empire and of the injustices perpetrated in India and previously unpublicized in England.

Although he championed many liberal and reform causes, Burke believed that political, social, and religious institutions represented the wisdom of the ages; he feared political reform beyond limitations on the power of the crown. Consequently, his Reflections on the Revolution in France (1790) made him the spokesman of European conservatives. His stand against the French Revolution—and, by implication, against parliamentary reform—caused him to break with Fox and his Whigs in 1791. Burke's Appeal from the New to the Old Whigs (1791) shows how closely he approached the Tory position of the younger William Pitt. He withdrew from political life in 1795.

Burke left, in his many and diverse writings, a monumental construction of British political thought that had far-reaching influence in England, America, and France for many years. He held unrestricted rationalism in human affairs to be destructive. He affirmed the utility of habit and prejudice and the importance of continuity in political experience. The son of a Protestant father and a Roman Catholic mother and himself a Protestant, he never ceased to criticize the English administration in Ireland and the galling discrimination against Catholics.