Donghai (East Sea) may refer to:

• East China Sea, also known as Donghai from its Chinese name (东海), a marginal sea east of China
  • East Sea (Chinese literature), one of the Four Seas, a literary name for the boundaries of China
• Donghai County (东海县), of Lianyungang, Jiangsu
• Donghai Island (东海岛), island in Zhanjiang, Guangdong
• Donghai Subdistrict (东海街道)
  • Donghai Subdistrict, Quanzhou, in Fengze District, Quanzhou, Fujian
  • Donghai Subdistrict, Lufeng, Shanwei, Guangdong
  • Donghai Subdistrict, Jixi, in Chengzihe District, Jixi, Heilongjiang
  • Donghai Subdistrict, Tianjin, in Hexi District, Tianjin
• Towns named Donghai (东海镇)
  • Donghai, Putian County, Fujian
  • Donghai, Jidong County, Heilongjiang
  • Donghai, Qidong, Jiangsu
• Donghai Commandery, historical commandery in present-day Shandong and Jiangsu

• Đông Hải District, in Bac Lieu Province, Vietnam

• East Sea (disambiguation)
• Nanhai (disambiguation) ("South Sea")
• Beihai (disambiguation) ("North Sea")
• Xihai (disambiguation) ("West Sea")
• 東海 (disambiguation), the East Asian script for "East Sea"
  • Donghae (disambiguation), Korean romanization
  • Tōkai (disambiguation), Japanese romanization
  • Tunghai (disambiguation), Wade–Giles romanization