Captain William Cornwallis Symonds (1 August 1810[6] – 23 November 1841) was a British Army officer who was prominent in the early colonisation of New Zealand.

[7] He came to New Zealand in the early 1830s as an agent of the Waitemata and Manukau Land Company and was instrumental in the founding of Auckland and the signing of the Treaty of Waitangi.

He was one of Governor William Hobson's closest and most effective officials and was one of the first six Police Magistrates in New Zealand.

[7] After the signing of the Treaty of Waitangi in 1840, Symonds was summoned to testify at the Crown Land Commission to examine the private land deal that led to the creation of Cornwallis, however the court was dissatisfied at the lack of information around the trade goods that were given to Ngāti Whātua, and banned logging activities at Cornwallis for two years until the agreement could be settled.

He died in a boating accident on 23 November 1841, while sailing across the Manukau Harbour to deliver supplies to the sick wife of missionary James Hamlin on the Āwhitu Peninsula.