Charles François Dumouriez was born in Cambrai. His father served as a commissary of the royal army, and educated his son most carefully and widely. The boy continued his studies at the college of Louis-le-Grand, and in 1757 began his military career as a volunteer in the campaign of Rossbach. He received a commission for good conduct in action, and served in the later German campaigns of the Seven Years' War with distinction; but at the peace he was retired as a captain, with a small pension and the cross of St Louis.
Dumouriez then visited Italy and Corsica, Spain and Portugal, and his memorials to the duc de Choiseul on Corsican affairs led to his re-employment on the staff of the French expeditionary corps sent to the island, for which he gained the rank of lieutenant-colonel. After this he became a member of the Secret du roi, the secret service under Louis XV, where his fertility of diplomatic resource had full scope. In 1770 he undertook a mission into Poland, where in addition to his political business he organized a Polish militia. The fall of Choiseul (1770) brought about his recall, and somewhat later he found himself imprisoned in the Bastille, where he spent six months, occupying himself with literary pursuits. He was then removed to Caen, where he remained in detention until the accession of Louis XVI in 1774.
Upon his release Dumouriez married his cousin Mademoiselle de Broissy, but he proved neglectful and unfaithful, and in 1789 the pair separated, Madame Dumouriez taking refuge in a convent. Meanwhile Dumouriez had devoted his attention to the internal state of his own country, and amongst the very numerous memorials which he sent in to the government was one on the defence of Normandy and its ports, which procured him in 1778 the post of commandant of Cherbourg, which he administered with much success for ten years. He became maréchal de camp in 1788; but his ambition was not satisfied, and at the outbreak of the Revolution, seeing the opportunity for carving out a career, he went to Paris, where he joined the Jacobin Club. The death of Mirabeau, to whose fortunes he had attached himself, proved a great blow to him; but, promoted to the rank of lieutenant-general and commandant of Nantes, his opportunity came after the flight to Varennes, when he attracted attention by offering to march to the assistance of the Assembly. He now attached himself to the Girondist party, and on 15 March 1792 became minister of foreign affairs. He played a major part in the declaration of war against Austria (April 20), and he planned the invasion of the Low Countries. On the king's dismissal of Roland, Clavière and Servan (13 June 1792), he took Servan’s post of minister of war, but resigned it two days later on account of King Louis's refusal to come to terms with the Assembly, and went to join the army of Marshal Luckner. After the émeute of 10 August 1792 and Lafayette’s flight he gained appointment to the command of the "Army of the Centre", and at the same moment France's enemies assumed the offensive. Dumouriez acted promptly. His subordinate Kellermann repulsed the Prussians at Valmy (20 September 1792), and Dumouriez himself severely defeated the Austrians at Jemappes (6 November 1792).
Returning to Paris, Dumouriez encountered popular ovation; but he gained less sympathy from the extremists in power; his old-fashioned methodical method of conducting war exposed him to the criticism of the ardent Jacobins, and a defeat would mean the end of his career. Defeat coming to him at Neerwinden in January 1793, he ventured all on a desperate stroke. Arresting the commissaries of the Convention sent to inquire into his conduct, he handed them over to the enemy, and then attempted to persuade his troops to march on Paris and overthrow the revolutionary government. The attempt failed, and Dumouriez, with the duc de Chartres (afterwards King Louis Philippe) and his brother the duc de Montpensier, fled into the Austrian camp.
Dumouriez now wandered from country to country, occupied in ceaseless intrigues with Louis XVIII, or for setting up an Orleanist monarchy, until in 1804 he settled in England, where the government granted him a pension. He became a valuable adviser to the British War Office in the struggle against Napoleon, though the extent of his aid only became public many years later. In 1814 and 1815 he endeavoured to procure from Louis XVIII the baton of a marshal of France, but failed to do so. He died at Turville Park, near Henley-on-Thames, on 4 March 1823.
Dumouriez's memoirs appeared at Hamburg in 1794. An enlarged edition, La Vie et les mémoires du Général Dumouriez, appeared at Paris in 1823. Dumouriez also wrote a large number of political pamphlets.