You Prefecture or You Province, also known by its Chinese name Youzhou, was a prefecture (zhou) in northern China during its imperial era.

"You Province" was cited in some ancient sources as one of the nine or twelve original provinces of China around the 22nd century BC, but You Prefecture was used in actual administration from 106 BC to the tenth century. As is standard in Chinese, the same name "Youzhou" was also often used to describe the prefectural seat or provincial capital from which the area was administered.

You was first created in 106 BC as a province-sized prefecture during the Western Han dynasty to administer a large swath of the dynasty's northern frontier that stretched from modern-day Shanxi Province in the west and Shandong Province in the south, through northeastern Hebei Province, southern Liaoning Province and southern Inner Mongolia to Korea. The prefectural capital was the City of Ji in modern Beijing. This prefecture continued to be centered in northern Hebei through the Three Kingdoms and Western Jin dynasty.

In the Sixteen Kingdoms period, several of the kingdoms that ruled northern China used "You" to name commandery-sized prefectures in their domain. When northern China was unified under a single sovereign during the Northern dynasties, You became a commandery-sized prefecture based in modern Beijing. During the Sui dynasty, prefectures were not used as a level of administration, and You was renamed Zhuo Commandery (Zhuojun). You was revived during the Tang dynasty as a smaller, commandery prefecture; its capital Youzhou was within present-day Beijing. In the Five Dynasties period, You was one of Sixteen Prefectures ceded to the Khitans of Manchuria. Thereafter, the name You Prefecture was no longer used.

According to several ancient texts from the Warring States period (475–221 BC), You was one of the Nine Provinces of ancient China. Ancient Chinese histories use the Nine Provinces to describe the geographic division of China during the two earliest Chinese dynasties, the Xia (2070–1600 BC) and the Shang (1600–1046 BC). The "Book of Xia" in the Classic of History from the earlier Spring and Autumn period (771–476 BC) states that Yu the Great, founder of the Xia dynasty, divided China into Nine Provinces—Jizhou, Yanzhou, Qingzhou, Xuzhou, Yangzhou, Jingzhou, Yuzhou, Liangzhou and Yongzhou—and does not mention Youzhou as one of the nine. But the Erya from about the third century BC includes Youzhou and Yingzhou instead of Qingzhou and Liangzhou; the Lü's Annals of the Spring and Autumn Annals, compiled in 239 BC, includes Youzhou instead of Liangzhou; and the Rites of Zhou from the middle of the second century BC includes Youzhou and Bingzhou in place of Xuzhou and Liangzhou.

Subsequent texts describe as Youzhou as one of the Twelve Provinces of Ancient China. Sima Qian in the Records of the Grand Historian, written from 109 to 91 BC explains that Shun, sovereign who relinquished power to Yu the Great, felt the domain in north was too vast and created three new prefectures including Youzhou from Yanzhou. The Book of Han, completed in AD 111, also lists Youzhou as one of the Twelve Ancient Provinces.

All of these texts described Youzhou as essentially equivalent to the State of Yan, one of the seven powers of the Warring States era.

Youzhou was first instituted as an administrative unit in 106 BC during the Han dynasty. In 106 BC, Emperor Wu of Han organized the Western Han dynasty into 13 province-sized prefectures, each administered by a cishi (刺史) or inspector. You Prefecture comprised the Shanggu, Zhuo, Guangyang, Dai, Bohai, Yuyang, Right Beiping, Liaoxi, Liaodong, Xuantu and Lelang Commanderies. Altogether the eleven commanderies contained 173 counties. The prefectural seat was the City of Ji in Guangyang Commandery, which is part of modern Beijing Municipality. Youzhou was bordered by Bingzhou (present-day eastern and northern Shanxi) in the west, Jizhou (southern Hebei) and Qingzhou (northern Shandong) in the south, Korea in the east and the steppes in the north.