Newcastle Local Municipality is one the three local municipalities that make up Amajuba District Municipality, with the others being Dannhauser and eMadlangeni
Local Municipalities. It is located on the North-Western of the KwaZulu-Natal Province and borders onto Free State and Mpumalanga Provinces to the West and North respectively. The local municipalities of eMadlangeni and Dannahauser Local Municipalities are located along the Eastern and Southern boundaries of Newcastle. Spatially Newcastle covers an area of approximately 1 854km2 in extent. A high majority of the people (80%) within Newcastle resides within the Newcastle East area, which is predominantly township and semi-rural areas characterised by a general lack of adequate infrastructure.
According to the most recent Community conducted Newcastle (KZN252) remains the highest contributor in terms of population growth within Amajuba District Municipality. As of 2016, the population of Newcastle is recorded at 389 117 people, thus marking a 7,1 % increase (25 881 people) over a 5-year period from the year 2011 (363 236 people). This means that on average, Newcastle has experienced a 1,42% annual growth
rate, which translates to 5 176 people per year. Newcastle has also experienced a significant increase in the total youth proportion of the population. In terms of the wider KwaZulu-Natal Province, Newcastle ranks 2nd as the local municipality with the highest number of people when compared to other local municipalities, with the highest being the Msunduzi Local Municipality. The population of Newcastle is spread unevenly over 34 wards as per the outcomes of the recent ward delimation process by the Dermarcation Board, marking a 3 wards increase.