The name "Trentham" was initially given by Richard Barton, the first European Settler in the area, in honour of his former employer, the Duke of Sutherland. One of the Duke of Sutherland's subsidiary titles was Viscount Trentham, of Trentham in the County of Stafford.
Trentham is one of New Zealand's most recognised racing venues. Thousands of horse racing enthusiasts flock to Upper Hutt throughout January for the Trentham races at the Trentham Racecourse. On Wellington cup day the racecourse is buzzing with visitors – both young and old.
Barton’s Bush is located in Trentham, as is Trentham Memorial Park.
Trentham Army Camp is a New Zealand Defence Force facility located in Trentham, Upper Hutt. Military Camp is a base for the NZ Army and Defence Force. Headquarters Joint Forces New Zealand (HQ JFNZ) was established at Trentham on 1 July 2001.
Schools are Trentham Kindergarten, HIBS and Trentham Primary School.