Binjai, formally Kota Binjai, is an independent city in the North Sumatra province of Indonesia, bordered by Deli Serdang Regency to the east and Langkat Regency to the west. Binjai is connected to Medan, about 22 km to the east, by the Sumatra highway that goes to Banda Aceh, and effectively forms a part of Greater Medan. The city's population was 181,904 in the 1990 Census, 224,516 in the 2000 Census, 246,154 in the 2010 Census, and 291,842 in the 2020 Census; the official estimate as of mid-2023 was 303,272, comprising 151,627 males and 151,645 females. In mid-2023, a further 49,217 inhabitants lived in Binjai District of Langkat Regency, outside the city limits but immediately north of the city.

Deli Serdang is a regency in the Indonesian province of North Sumatra. It surrounds the city of Medan, and also borders to the west the city of Binjai, which is effectively a bedroom community for Medan. The entire regency lies within the Medan metropolitan area. It occupies an area of 2,241.68 km2. The capital of the district is Lubuk Pakam, which is located approximately 30 km east of Medan. The national census of 2000 recorded 1,573,987 people, but by 2010 the regency's population increased by 13.76% to 1,790,431, and at the 2020 Census the total was 1,931,441. The official estimate as at mid 2023 was 2,018,164. Kualanamu International Airport is located in this regency.