Ninghai or Ning Hai is a county in Ningbo Prefecture, Zhejiang Province, China.

It is also the atonal pinyin romanization of various Chinese names and words, particularly Nínghǎi {{nowrap|(t {{lang|zh|{{linktext|寜海}}}},}} {{nowrap|s {{lang|zh|{{linktext|宁海}}}})}} meaning "peaceful", "pacified", or "pacifying the sea(s)".

It may refer to:

• Ninghai, a medieval village on the shores of Houhai Lake now known as Qiaodou Village in Licheng District in Putian, Fujian, China
• Ninghai Bridge, an ancient stone bridge over a branch of the Mulan in Qiaodou
• Ninghai New Bridge across the Mulan in Putian
• Chinese cruiser Ning Hai, a light cruiser in the Chinese fleet
• Ning Hai-class cruisers, including the Ning Hai and its sister ship
• Muping District, which was formerly known as "Ninghai"

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