Selwyn District is located in central Canterbury in New Zealand’s South Island. It extends from the Waimakariri River in the north to the Rakaia River in the south, and from the Southern Alps in the west to the Pacific Ocean in the east. It covers approximately 6,381 square kilometres and has a population of about 87,600.

The district council is based in Rolleston, an important local commercial and industrial centre. Major towns include Rolleston, Lincoln, Prebbleton and Darfield.

The economy is based on agriculture and pastoral farming, food processing, manufacturing, logistics and warehousing, education and research, and services. Livestock farming includes dairy cattle, beef cattle, sheep, deer and horses, while cropping focuses on grain, fodder, vegetables and horticultural crops. Rapid population growth and economic diversification in recent years have supported the expansion of construction, manufacturing, logistics and business services.

Lincoln University and research institutions such as Plant & Food Research, located in Lincoln, make the district an important New Zealand centre for agricultural technology, food research and sustainable land use.

Rewi Alley, the renowned New Zealand friend of China, was born in Springfield in Selwyn District. Selwyn established a sister-district relationship with Shandan County, Gansu Province, in 2009.

The current mayor is Lydia Gliddon.