The Commander-in-Chief of the Forces, or just the Commander-in-Chief (C-in-C), was the professional head of the British Army from 1672 until 1904, when the office was replaced by the Chief of the General Staff, soon to become Chief of the Imperial General Staff. From 1855, the C-in-C was subordinate to the Secretary of State for War. The relationship between the Commander in Chief and another office, the Captain-General, was never clear. On occasion, the two posts were held by the same man.

In most instances, Commanders-in-Chief of the Forces were not cabinet members. Instead, the British Army was represented variously in government by the Paymaster of the Forces (Paymaster-General), Master-General of the Ordnance, Secretary at War, Secretary of State for War and the Colonies, Secretary of State for War or Secretary of State for Defence.

Commanders-in-Chief of the Forces

• General James Scott, 1st Duke of Monmouth (1674–1679)
• Vacant (1679–1690)
• General John Churchill, 1st Earl of Marlborough (1690–1691)
• General Meinhard Schomberg, 1st Duke of Leinster (1691–1711)
• General James Butler, 2nd Duke of Ormonde (1711–1714)
• Vacant (1714–1744)
• Field Marshal John Dalrymple, 2nd Earl of Stair (1744)
• Field Marshal George Wade (1745–1748)
• Vacant (1748–1757)
• Field Marshal John Ligonier, 1st Viscount Ligionier (1757–1759)
• Vacant (1759–1766)
• General John Manners, Marquess of Granby (1766–1769)
• Vacant (1769–1778)
• General Jeffrey Amherst, 1st Lord Amherst (1778–1782)
• General Henry Seymour Conway (1782–1783)
• General Jeffrey Amherst, 1st Lord Amherst (1783–1795)
• Field Marshal Prince Frederick, Duke of York (1795–1809)
• General Sir David Dundas (1809–1811)
• Field Marshal Prince Frederick, Duke of York (1811–1827)
• Field Marshal Arthur Wellesley, 1st Duke of Wellington (1827–1828)
• General Rowland Hill, 1st Lord Hill (1828–1842)
• Field Marshal Arthur Wellesley, 1st Duke of Wellington (1842–1852)
• Field Marshal Henry Hardinge, 1st Viscount Hardinge (1852–1856)
• Field Marshal Prince George, 2nd Duke of Cambridge (1856–1895)
• Field Marshal Garnet Wolseley, 1st Viscount Wolseley (1895–1900)
• Field Marshal Frederick Roberts, 1st Earl Roberts (1900–1904)