North Sumatra (Indonesian: Sumatera Utara) is a province of Indonesia on the Sumatra island. Its capital is Medan. It is the most populous Indonesian province outside of Java. It is slightly larger than Sri Lanka in area.

The province of North Sumatra stretches across the island of Sumatra between the Indian Ocean and the Strait Malacca. It borders Aceh province on the northwest and Riau and West Sumatra provinces in the southeast. It has an area of 70,787 km². The province contains a broad, low plain along the Strait of Malacca on which the provincial capital, Medan, is located. In the south and west, the land rises to the mountain range that runs the length of Sumatra; the mountains here are dominated by Lake Toba, formed from the caldera of an ancient volcano. Several large islands in the Indian Ocean off the coast of Sumatra are part of North Sumatra, most notably Nias, and the Batu Islands.

North Sumatra recorded a population of 11.48 million in the 2000 national census. An Intercensal estimate for 2007 shows a population of 12,834,371, 2010 census recorded 12,985,075 people, a sex ratio of 99.59 men per 100 women.