Hải Hậu [ha̰ːj˧˩˧:hə̰ʔw˨˩] is a rural district of Nam Định province in the Red River Delta region of Vietnam.

Hải Hậu is divided into 34 commune-level subdivisions.

The district covers an area of 227 km2.

As of 2003 the district had a population of 285,298.

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