The Manawatū Estuary is an estuary at the mouth of the Manawatū River, near Foxton Beach in the lower North Island of New Zealand.

It is a wetland of international significance as one of seven Ramsar sites in New Zealand.

At approximately 250 hectares (620 acres),[2] the Manawatū Estuary is the largest estuary in the lower North Island.

[3] A total of 93 different bird species have been identified at the estuary.

[4] During spring migratory birds arrive for the summer at the estuary, including the bar-tailed godwit, red knot, Pacific golden plover, Japanese snipe, wandering tattler and whimbrel.