Emperor Ming of Liu Song ((劉)宋明帝; 9 December 439 – 10 May 472), personal name Liu Yu (劉彧), courtesy name Xiubing (休炳), childhood name Rongqi (榮期), was an emperor of the Chinese Liu Song dynasty. He became emperor after his violent and impulsive nephew Liu Ziye was assassinated in January 466, as he was regarded as more lenient and open-minded at first. However, he soon turned cruel and suspicious as well after becoming emperor, and during his reign, his nephews and brothers were nearly all slaughtered on his orders. This greatly weakened the Liu Song dynasty and contributing to its fall in 479, just seven years after his death.

Liu Yu was born in 439, as Emperor Wen's 11th son. His mother Consort Shen Rongji (沈容姬) was a low-ranked imperial consort with the title Meiren (美人). For reasons unknown, Wen once wanted to put her to death, but she convinced him that killing her would offend the spirit of his deceased wife, Empress Yuan Qigui, and she was spared. In 448, Liu Yu was created the Prince of Huaiyang. In 452, his title was changed to Prince of Xiangdong. Consort Shen died in 453, the same year that Emperor Wen was assassinated by his crown prince Liu Shao, who took over as emperor and subsequently put a number of his brothers, including Liu Yu, under house arrest, but Liu Yu and the other brothers were released when another older brother, Liu Jun the Prince of Wuling, defeated and killed Liu Shao and took the throne himself (as Emperor Xiaowu). Emperor Xiaowu posthumously honored Liu Yu's mother Consort Shen as Princess Dowager of Xiangdong, and Emperor Xiaowu's mother Empress Dowager Lu Huinan took over the duties of raising Liu Yu to adulthood. As he grew, as was customary for Liu Song imperial princes, he was rotated through governorships of commanderies and provinces. Liu Yu was regarded as a kind and open-minded man, with substantial literary abilities. He was also said to be grossly overweight.

In 464, Emperor Xiaowu died, and was succeeded by his son Emperor Qianfei. Emperor Qianfei was impulsive and violent, and he, after discovering and brutally suppressing a plot to depose him in favor of his granduncle Liu Yigong (劉義恭) the Prince of Jiangxia, suspected his uncles as well, and had them returned to the capital and confined. Of his uncles, he particularly suspected Liu Yu, Liu Xiuren (劉休仁) the Prince of Jian'an, and Liu Xiuyou (劉休祐) the Prince of Shanyang, since they were the oldest. Another even older uncle, Liu Hui (劉褘) the Prince of Donghai, was considered so unintelligent that Emperor Qianfei did not view him as much of a threat.

Because these three princes were all overweight, he had them put in cages and weighed as if they were pigs. As Liu Yu was the heaviest, he called Liu Yu the Prince of Pigs, Liu Xiuren the Prince of Murderers, and Liu Xiuyou the Prince of Thieves. He often humiliated Liu Yu by putting him in stables and feeding him the way that pigs would be fed. He wanted to kill Liu Yu, Liu Xiuren, and Liu Xiuyiu, but each time Liu Xiuren flattered him and caused him to change his mind. In one particular incident, he tied Liu Yu up like how a pig would be tied up, and had him delivered to the kitchen, stating "Today is pig-killing day." Liu Xiuren, however, said "This is not the pig-killing day." He angrily asked Liu Xiuren why that was the case, and Liu Xiuren stated: "Wait after your son is born, then kill the pig and take out his entrails!" Emperor Qianfei liked Liu Xiuren's joke and spared Liu Yu.

In winter 465, around the time that Emperor Qianfei made his second wife, Lady Lu, empress, there weren't enough palace eunuchs to prepare for the ceremony, so Emperor Qianfei called for the eunuchs from the princes' mansions to come over to help. Liu Yu sent his own personal eunuch, Qian Lansheng (錢藍生), to observe Emperor Qianfei's actions and report to him. Meanwhile, some attendants of Emperor Qianfei were plotting to kill him. When the emperorwas carrying out a ghost-shooting ritual after dreaming of the spirit of a lady-in-waiting that he had killed, the attendant Shou Jizhi (壽寂之) rushed in and assasinated him. With support from the officials and particularly with his brother Liu Xiuren as a major advocate, Liu Yu was declared emperor (as Emperor Ming).

Emperor Ming posthumously honored his mother Consort Shen as Empress Dowager Xuan but, because he was raised by Emperor Xiaowu's mother Grand Empress Dowager Lu, he continued to honor her as empress dowager. He also tried to pacify the empire by promoting the various officials, his brothers, and some of his nephews. (However, he forced Emperor Qianfei's oldest younger brother Liu Zishang (劉子尚) the Prince of Yuzhang, and his sister Liu Chuyu the Princess Kuaiji, both born also of Empress Wang Xianyuan and both of whom participated in his ill-fated governance, to commit suicide.) He created his wife Princess Wang Zhenfeng empress.

One of the nephews that he tried to promote, Liu Zixun the Prince of Jin'an, whose chief of staff Deng Wan (鄧琬) had just prior to Emperor Qianfei's death declared a rebellion against Emperor Qianfei, refused, and instead declared a rebellion against Emperor Ming, in association with Yuan Yi (袁顗) the governor of Yong Province (雍州, modern northwestern Hubei and southwestern Henan) and Liu Zisui's chief of staff Xun Bianzhi (荀卞之). They accused Emperor Ming of being an usurper and having unduly killed Liu Zishang. Jing Province (荊州, modern central and western Hubei) and Kuaiji Commandery (the southern shore of Hangzhou Bay), governed by Liu Zixun's brothers Liu Zixu (劉子頊) the Prince of Linhai and Liu Zifang (劉子房) the Prince of Xunyang, also quickly rose in support. In spring 466, Deng Wan, claiming to have received a secret edict from Liu Zixun's grandmother Empress Dowager Lu Huinan, declared Liu Zixun emperor. Upon the declaration, nearly the entire empire declared for Liu Zixun, with Emperor Ming only in control of the region immediately around the capital Jiankang.

However, Liu Zixun's generals proceeded slowly, believing that Jiankang would collapse on its own due to the lack of food supply. Emperor Ming's general Wu Xi (吳喜) was quickly able to advance east and capture Liu Zifang, taking the commanderies around Kuaiji that had declared for Liu Zixun and securing a food supply. The troops of Liu Zixun and Emperor Ming stalemated for months in the Chaohu region, until Emperor Ming's general Zhang Xingshi (張興世) built a defense post at Qianxi (錢溪, in modern Chizhou, Anhui), upstream from Liu Zixun's main troops commanded by Yuan Yi and Liu Hu (劉胡), cutting off their food supplies. As Liu Hu then tried to capture Qianxi to reopen food routes, he was defeated by Zhang and Shen Youzhi, and Liu Hu and Yuan then fled, with their troops collapsing. Liu Hu fled back to Xunyang, but then left under guise that he was going to set up perimeter defenses while instead fleeing. Xunyang was left without a defense, and Deng Wan contemplated killing Liu Zixun to save himself, but instead was killed by another staff member Zhang Yue (張悅). Shen then arrived and executed Liu Zixun, ending his rival claim.