Joseph McMullen Dargaville (1837 – 27 October 1896) was a 19th-century Member of Parliament from Auckland, New Zealand.

Joseph McMullen Dargaville was born in Cork, Ireland, the son of Anderson Dargaville, a physician, and his wife, Eliza McMullen. He was descended from Huguenots, who had fled to Ireland to escape persecution. He was baptised on 27 June 1837 and presumed to have been born earlier that same year. He attended Fermoy College.^[1]

Dargaville emigrated with his brothers to Victoria. In early 1859 he relocated again, this time to Sydney, where he obtained a clerking job with the Union Bank of Australia at a salary of £100 per annum. From 1860 to 1866 he worked in several branches of the bank in New South Wales, Tasmania and Victoria.^[1]

On 20 April 1865 at Portland, Victoria, he wed Anne Must, daughter of Thomas and Anne Must; the couple had at least six children.^[1] His wife was born on 1 May 1845 in Sydney, they had two sons and five daughters.^[2]

Dargaville would represent Auckland East on the Auckland Provincial Council from 1873 to 1876.^[1]

He stood unsuccessfully for the City of Auckland West in the 1875 by-election, then represented the electorate from 1881 to 1887.^[3]

In the 1887 election, he stood in the Marsden electorate and was defeated by Robert Thompson (955 to 550 votes).^[4]

In the 1890 election election, he stood in the Bay of Islands electorate against three others (Robert Houston, James Trounsen, and John Lundon) and came last.^[5]

He contested the Bay of Islands electorate again in the 1893 election against two others (Houston and Trownson) and again came last.^[6]

He founded the Northland town of Dargaville, named for him. He was a prominent businessman and timber merchant there.^[1]

He was a member of the Orange Order.^[7]

Dargaville was on a return visit from England when he died aboard the Mariposa on 27 October 1896, and was buried at sea.^[1] He has a memorial at the St Stephens Cemetery in Parnell, Auckland, shared with his wife Anne, who died on 5 July 1915.