Chillán is the capital city of the Ñuble Region in the Diguillín Province of Chile located about 400 km (249 mi) south of the country's capital, Santiago, near the geographical center of the country. It is the capital of the new Ñuble Region since 6 September 2015. Within the city are a railway station, an inter-city bus terminal named María Teresa, and a regimental military base. The city includes a modern-style enclosed shopping mall in addition to the multi-block open-air street market where fruits, vegetables, crafts and clothing are sold. The nearby mountains are a popular destination for skiing and hot spring bathing.

The Ñuble Region officially the Region of Ñuble, is — since 5 September 2018 – one of Chile's sixteen regions. It spans an area of 13,178.5 km2 (5,088 sq mi), making it the smallest region in Chile in terms of area, and is administratively constituted by 21 communes. It has a population of 480,609 inhabitants. Its capital is the city of Chillán.