Eru Bay (Estonian: Eru laht, also Estonian: Mungalaht) is bay in Kuusalu Parish (Harju County) and Haljala Parish, Lääne-Viru County in Estonia; the bay is part of Gulf of Finland. Area of the bay is 7656 ha.[1]
The bay is bordered by Pärispea Peninsula and Käsmu Peninsula.
Loobu River drains into Eru Bay.