[5] Horowhenua District was established in 1989 from a merger of Horowhenua County, Foxton Borough, Levin Borough and part of the first Manawatū District, as part of New Zealand local government reforms.

The results were 79.3% European (Pākehā); 27.7% Māori; 7.3% Pasifika; 4.9% Asian; 0.6% Middle Eastern, Latin American and African New Zealanders (MELAA); and 2.4% other, which includes people giving their ethnicity as "New Zealander".

Of those at least 15 years old, 2,904 (9.7%) people had a bachelor's or higher degree, 16,785 (55.8%) had a post-high school certificate or diploma, and 9,531 (31.7%) people exclusively held high school qualifications.

[7] Much of the area was once an extensive wetland and the centre of a substantial flax industry.

It has been progressively drained and converted to productive but flood-prone farmland, with a mixture of loam and peat based soils.

Some parts of the wetland, particularly those around Lake Horowhenua are being returned to their former state as a conservation area, with the help of local Māori.

Secondary: Primary: Intermediate: In rugby, a combined Horowhenua-Kapiti team represents the area in the amateur Heartland Championship.