The Chindits, officially known as Long Range Penetration Groups, were special operations units of the British and Indian armies which saw action in 1943–1944 during the Burma Campaign of World War II. Brigadier Orde Wingate formed them for long-range penetration operations against the Imperial Japanese Army, especially attacking lines of communication deep behind Japanese lines.

The name Chindits is a corrupted form of Chinthe (Burmese: ခြင်္သေ့), Burmese word for "lion".

Their operations featured long marches through extremely difficult terrain, undertaken by underfed troops often weakened by diseases such as malaria and dysentery. Controversy persists over the extremely high casualty rate and the debatable military value of the achievements of the Chindits.

During the East African Campaign of 1940–41, Wingate – under General Archibald Wavell, Commander-in-Chief of the Middle East Command – had begun to explore guerilla tactics, when he created and commanded a unit known as Gideon Force, composed of regular troops from Sudan and Ethiopia, as well as Ethiopean partisans. Gideon Force disrupted Italian supply lines and collected intelligence.

In 1942, after the disbandment of Gideon Force, Wavell – who had since been appointed Commander-in-Chief, India in New Delhi – requested the services of Wingate in Burma. It was intended that he would raise irregular forces to operate behind the Japanese lines, in a manner similar to Gideon Force. Wingate arrived in Burma in March 1942 and for two months, as Japanese forces advanced rapidly, toured the country developing his theories of long-range penetration, during the two months preceding the Japanese conquest of Burma. After returning to Delhi, he presented his proposals to Wavell.

The first Chindit unit, the 77th Indian Infantry Brigade, was gradually formed in the area around Jhansi in the summer of 1942. Wingate took charge of the training of the troops in the jungles of central India during the rainy season. Half of the Chindits were British: the 13th Battalion, the King's Liverpool Regiment (nominally a second-line battalion, which contained a large number of older men) and men from the former Bush Warfare School in Burma, who were formed into 142 Commando Company. The other portion of the force consisted of the 3rd Battalion, the 2nd Gurkha Rifles (a battalion that had only just been raised) and the 2nd Battalion, the Burma Rifles (a composite unit formed from several depleted battalions of Burmese troops that had retreated into India in 1942).

Wingate trained this force as long-range penetration units that were to be supplied by stores parachuted or dropped from transport aircraft and were to use close air support as a substitute for heavy artillery. They would penetrate the jungle on foot, essentially relying on surprise through mobility to target enemy lines of communication (a tactic that the Japanese had previously used in 1942 to great effect against British forces in Malaya and Burma).

The standard brigade and battalion structures were abandoned. The force was instead formed into eight columns, each of which was organised as: an infantry rifle company (with nine Bren light machine guns and three 2-inch mortars); a support group with the heavy weapons (four Boys anti-tank rifles, two medium Vickers machine guns and two light anti-aircraft guns); a reconnaissance platoon from the Burma Rifles; and a sabotage group from 142 Commando Company. Small detachments from the Royal Air Force (equipped with radios to call in air support), Royal Corps of Signals and Royal Army Medical Corps were attached to the column headquarters. The heavy weapons, radios, reserve ammunition, and rations and other stores were carried on mules, which would also provide an emergency source of food once their loads had been depleted. With 57 mule handlers, each British column numbered 306 men (the Gurkha columns were slightly stronger, with 369 men).