Hill slopes in wine producing regions of the South Island of New Zealand are rarely developed for viticulture despite having the capability. Viticultural development in these wine producing regions is primarily limited to flat areas despite the benefits of hill slopes that can increase productivity and variability of the grapes grown. The objective of this study is to assess the viability and development of hill slopes in the South Island of New Zealand with regards to industrial viticultural development. Site investigation in combination with background research identified five fundamental characteristics (i.e., elevation, slope angle, aspect, temperature and rainfall) that are required for proper assessment as well as industrial viticultural practices and concerns specific to the South Island. A slope angle of 15° was determined to be suitable for viticultural development as this angle is the maximum angle for machinery to work and operate safely. Additionally, this slope angle encourages the benefits that hill slopes provide and slope stability issues are limited. GIS suitability mapping demonstrates that ~0.7% of the South Island of New Zealand is viable for hill slope viticultural development using elevation, slope angle, aspect, temperature and rainfall characteristics to produce the maps. Temperature and sunlight relationships via data logger analysis support the various benefits that hill slope development provides, including increasing the number of growing degree days (GDD) by 1, increasing air and soil temperature and increasing sunlight exposure by 3,000 Lux. Overall, findings identify the extent and benefits that hill slopes may provide in major grape regions within the South Island of New Zealand.