General Sir James Yorke Scarlett GCB (1 February 1799 – 6 December 1871) was a British Army officer who served in the Crimean War. He led the Charge of the Heavy Brigade during the Battle of Balaclava on 25 October 1854.

The second son of the 1st Baron Abinger, he was born in London and educated at Eton and Trinity College, Cambridge. In 1835, he married Charlotte Anne Hargreaves, a coal heiress from Burnley, the town becoming his adopted home.

Scarlett entered the army in 1818, as a cornet in the 18th Hussars; in 1830, he became a major in the 5th Dragoon Guards, whose Colonel was Sir John Slade (1762-1859). Slade served in the Peninsular War, where he was described as an officer of 'limited ability, lacking initiative and nearly useless' and 'that damned stupid fellow.' Combined with Slade's age, this resulted in Scarlett's appointment as Commanding Officer of the regiment in 1840, a post he held for nearly fourteen years. In 1854 he was close to retirement after an uneventful career during which he had not seen any active service. In this he was typical of the senior ranks of the British cavalry at the time, other than those posted to India.

In April 1854 Colonel Scarlett was appointed Brigadier-General of the Heavy Brigade of Cavalry, under Lord Lucan, Commander of the Cavalry Division. The 5th Dragoon Guards formed part of Scarlett's Heavy Brigade which was sent to the Black Sea in 1854. There it suffered heavily from cholera in the camps of Varna.

During the Battle of Balaclava on the morning of 25 October 1854, the Russians had stormed a series of hills known as the Causeway Heights beyond which lay the "Valley of Death" where the Earl of Cardigan would lead the Light Brigade in one of the great military blunders of the nineteenth century.

Lord Raglan ordered Scarlett to move eight squadrons of his brigade back to Kadikoi, to support the 93rd Highlanders defence of the British base at Balaklava. As Scarlett led his column of the Heavy Brigade across the sprawling tented camp of the Light Brigade, a Russian cavalry force of approximately 2000 was spotted just 800 yards from their left flank, at the top of the heights.

The 55-year-old Scarlett quickly assembled just 300 of his Inniskillings and Scots Greys at the foot of the heights, organising them into parade-perfect formation, and sounded the charge. As onlookers watched from the rear, Scarlett led his red-clad "Heavies" into the centre of the grey mass of Russians. His attack was soon followed by rest of the column (the remainder of the Inniskillings and the 4th, and 5th Dragoon Guards). Even the two squadrons of 1st Royal Dragoons who had remained behind to hold the Brigade's original position attacked on their own initiative. This action became known as the Charge of the Heavy Brigade and caused the enemy formation to collapse completely. The Russians were routed and retreated across the heights into the valley that would soon be the scene of the Light Brigade charge. Although successful, it defied military doctrine of the time, as the Russians were more numerous and, more importantly, the charge was made uphill against an oncoming force.

Cardigan had observed the action with his "Lights" from a short distance away, and had he used his initiative and chosen this moment to finish what Scarlett had started, the Charge of the Light Brigade might well have been remembered as a success. Later when Cardigan finally led his men into the valley, the Earl of Lucan, Scarlett and the Heavies waited in reserve. Scarlett had started to advance in the hope of salvaging something from the disaster when Lucan, fearing the complete loss of the Light Brigade, sounded the retreat.