It is the largest town in the Wairarapa, a geographical region that is separated from metropolitan Wellington by the Rimutaka ranges. It is 100 kilometres north-east of Wellington, 28 kilometres south of Eketahuna, and stands on the Ruamahanga River.
Masterton is a thriving community with an urban population of 19,900, and district population of 23,100 (June 2008 estimates). It did not quite qualify to be a city by 1989 when the minimum population requirement for that status was lifted from 20,000 to 50,000. The Wairarapa Line railway, which opened to Masterton on 1 November 1880, allows many residents easy access to work in the cities of Wellington, Lower Hutt and Upper Hutt.
Named after pioneer Joseph Masters, it was first settled by Europeans on 21 May 1854. It gained borough status in 1877, and the Masterton District is now part of the Greater Wellington Region.
Local industries involve service industries for the surrounding farming community. The town is the headquarters of the annual Golden Shears sheep-shearing competition.