Mangawhai is a locality in Northland, New Zealand around the Mangawhai Harbour. The township of Mangawhai is at the south west extent of the harbour, and the township of Mangawhai Heads is 5 km north east. Kaiwaka is 13 km south west, and Waipu is 20 km north west of Mangawhai Heads. The population for the Mangawhai statistical district was 813 in the 2006 Census, an increase of 189 from 2001. The statistical district covers a significantly larger area than the township. The population for Mangawhai Heads was 852 in 2006, up 132 from 2001.
In the early and mid 19th century, Mangawhai Harbour was one of the main access points for the Kaipara. Ngāti Whātua used to drag waka from Kaiwaka to Mangawhai. A Ngā Puhi war party landed at Mangawhai in February 1825 (memorial plinth, Mangawhai Museum and all publications regarding Mangawhai early history) and moved 12 km inland to confront the Ngāti Whātua at Te Ika-a-ranga-nui near Kaiwaka. Later in the 19th century, settlers would travel by boat from Auckland to Mangawhai, walk to Kaiwaka, and then travel on the water again across the Kaipara Harbour. By the early 1860s, a dray road existed between Mangawhai and Kaiwaka.