Nogai, or Noğay (Kypchak and Turki: نوغای; also spelled Nogay, Nogaj, Nohai, Nokhai, Noqai, Ngoche, Noche, Kara Nokhai, and Isa Nogai; died 1299/1300) was a general and kingmaker of the Golden Horde. His great grandfather was Jochi, son of Genghis Khan.

Though he never formally ruled the Golden Horde himself, he was effectively the co-ruler of the state alongside whatever khan was in power at the time and had unrestricted control over the portions west of the Dnieper. At his height, Nogai was one of the most powerful men in Europe and widely thought of as the Horde's true head. The Russian chroniclers gave him the title of tsar, and the Franciscan missionaries in the Crimea spoke of him as a co-emperor. Nogai was also a notable convert to Islam.

French historian Paul Pelliot wrote that Nokhai meant "dog". Although in the Mongolian language, "nokhoi" (in Mongolian script: ᠨᠣᠬᠠᠢ, nokhai) literally means a "dog", it does not necessarily mean a particularly negative and insulting name in its context, since people were called "dogs" among the Mongols at the time and sometimes presently as "nokhduud" as in "you dogs (guys/men/people)". Genghis Khan also called his capable generals "dogs of war" or "men of war". This probably came about because Mongols had a lot of dogs, which were very useful for people's lives in hunting and alerting them to danger. Thus dogs became a big part of nomadic life and also played a big part in their religion. According to British historian J. J. Saunders, the name "Dog" was used to distract the attention of evil spirits (presumably, they would not be interested in a canine). The Mongols sometimes referred to the wolf as a "steppe dog".

Nogai was born to Tatar (Tutar), a son of Terval who was a son of Jochi. He would rule his grandfather's appanage after his father died. After the Mongol invasion of Europe, Batu Khan left Nogai with a tumen (10,000 warriors) in modern-day Moldavia and Romania as a frontier guard. He was a nephew of Berke Khan as well as Batu Khan and Orda Khan, and under his uncle, he became a powerful and ambitious warlord.

In his later years, Berke began to delegate more and more responsibility to his promising nephew. Nogai's leading role first appears, along with Talabuga, under famous Mongol general Burundai as a battle commander in 1259/1260. He was a young sub-commander during the second major Mongol raid against Poland, undertaken to pay for Berke's war against Hulegu. Here Nogai distinguished himself and plundered Sandomierz, Kraków and other cities.

Nogai's father Tatar died when he was serving under Hulegu.

In 1262, a civil war broke out between the Golden Horde and the Ilkhanate, with Berke and Hulegu supporting separate claimants for the title of khagan. Nogai Khan was given a high role in the army of the Golden Horde; Rashid Al-Din describes him as Berke's "commander-in-chief". He had a command of 30,000 men. He was first charged with raiding along the frontier into the territory of the Ilkhanate; Nogai made multiple reconnaissances in force into the Caucasus region, drawing Hulegu north with the bulk of his forces. He annihilated an advance guard under Shiramun, and raided as far as the Kur, but was himself repulsed near Shabran in December 1262, and forced to retreat. Nogai then took on the task of repelling Hulegu's attempted invasion, as the latter was emboldened; Hulegu marched north with his army to invade Berke's territory, attempting to envelope Nogai's army at the Terek, but found only an abandoned camp. While Hulegu's men were looting the camp, Nogai's troops surprised Hulegu's at the Terek River, cutting down a great many of them in an ambush. Hulegu rallied his men and a day-long battle ensued; the fighting was fierce, but the Golden Horde's initial advantage was too great. The Ilkhanate army was routed and many thousands of them were drowned while trying to flee, and the survivors fled back into Azerbaijan. This victory greatly enhanced Nogai's reputation in the Horde, and he was already a trusted lieutenant of Berke.

In August 1264, the war effectively ended when Kublai Khan was crowned khagan with the acknowledgement of Berke, Hulegu, and Chagatai. However the war was renewed between the Golden Horde and Ilkhanate in 1265. Nogai was given the task of leading an invasion of the Ilkhanate, now ruled by Hulegu's successor Abaqa Khan. He invaded Persia and plundered some areas before being met in battle by Abaqa on the Aksu. A fierce and severe battle ensued in which Nogai was personally injured (losing an eye) and his army was forced to retreat. Abaqa pursued Nogai's army across the Kur, hoping to wipe it out, but Abaqa was forced to withdraw when Berke arrived with reinforcements.