Matthew McCarten (born 11 February 1959) is a New Zealand political organiser and trade unionist, of Ngāpuhi descent. McCarten was active with several trade unions including the Hotel and Hospital Workers' Union, the Unite Union, and the One Union; the latter two of which he co-founded.

Matt McCarten is the youngest child of John and Rehina McCarten. He had two older brothers named Mike and John and an older sister named Margret. McCarten was placed into care following his birth and lived at the Catholic Home of Saint Vincent's in Herne Bay, Auckland until the age of two. According to McCarten, his mother had been led to believe that her fourth child had died at birth. She subsequently went into hiding and moved to Dunedin, cutting of all contact with McCarten's father and older siblings.

Until the age of 14, McCarten lived at several orphanages in Wellington, Ōtaki, and Marton. While living at the Brethren–run Marton Home, McCarten experienced violence at the hands of staff members. These formative years shaped his rejection of Christianity and liberal attitudes towards sex.

At the age of 14, his mother Rehina learned from his older brother John that Matt had not died at birth. He subsequently moved to Dunedin to live with her due to the death of his father. By that stage, Rehina had given birth to five other children through other relationships. After completing his education at the age of 15, McCarten spent several weeks in psychiatric care at Waikari Hospital following a failed bank robbery attempt, which he regarded as a turning point in his life.

After being discharged from Waikari Hospital, McCarten resumed his secondary education at a different school while working part-time cleaning and waitering jobs. Though McCarten passed his University Entrance exam, he decided to work at a hotel in Queenstown. There, he became involved in a successful industrial strike in opposition to his employers' policy of dismissing non-management workers following the summer season. He became a committed trade unionist. McCarten later described John Steinbeck's novel The Grapes of Wrath and George Orwell's Homage to Catalonia as influences on his political views. In addition, McCarten participated in a gay rights demonstration while visiting Brisbane at the age of 20.

McCarten later worked as a bartender at The Trans, then the biggest hotel in Queenstown. After spending eight or nine months living in travelling and working in Australia, McCarten worked as a bookmaker at a bar in Palmerston North before becoming a manager at the Fitzherbert Hotel. By 1981, McCarten was working for Dominion Breweries. Due to his opposition to Apartheid, he refused to serve members of the South Africa national rugby union team. At the time, McCarten was also a member of the Hotel and Hospital Workers' Union, which was affiliated with the Labour Party; making McCarten a member of the Labour Party.

McCarten later moved to Auckland where he worked as a manager, bartender and later helped establish the New Zealand Bartenders' Guild. With the support of his guild, he found a casual vacancy job on the executive of the Hotel and Hospital Workers' Union, working alongside several key trade union figures including Rick Barker and Mark Gosche, who later joined the Labour Party.

Following the 1984 New Zealand general election, the Hotel and Hospital Workers' Union organised a strike to demand a $20 minimum wage. While picketing the Sheraton Hotel near Auckland Airport, McCarten was arrested by the Police. As a result of the Auckland strike, nationwide stopwork meetings were held and the hotel industry subsequent agreed to implement a $20 minimum wage.