Terengganu River in the context of Sultan Mahmud Bridge

Terengganu (Malay pronunciation: [tərəŋɡanu]; Terengganu Malay: Tranung, formerly spelled Trengganu or Tringganu) is a sultanate and federal state of Malaysia. The state is also known by its Arabic honorific, Dāru l-Īmān ("Abode of Faith"). The coastal city of Kuala Terengganu, at the mouth of the Terengganu River, is both the state and royal capital as well as the most populous city in Terengganu. Other major cities and towns include Jerteh, Kuala Dungun, Chukai, Kuala Berang, Marang, and Permaisuri. At 13,035 square kilometres (5,033 sq mi) in size and a population of over 1.2 million people in 2023, Terengganu is Malaysia's 7th largest state and 10th most populated. Terengganu, along with Kelantan, Perlis, and the Federal Territory of Putrajaya, is one of the most homogeneous states/territories in the country of which 95% of the population are ethnic Malay-Muslims with its own distinct language/dialect, culture, history, and tradition.

Located on the east coast of Peninsular Malaysia, Terengganu borders the state of Kelantan to the north, Pahang to the west and south, and the South China Sea to the east. Terengganu is geographically divided into sparsely populated and mountainous inland (known as the Terengganu Highlands of which the highest point is Mount Lawit at 1,519 metres (4,984 ft)) that span from the border with Kelantan to Kemaman district and largely flat coastal plains where most of the state's 1.1 million people are concentrated. The state is known for having the longest coastline in Peninsular Malaysia and achieved an entry in the Malaysian Book of Records for having the cleanest beach in the country. Many of the most popular islands in Malaysia are located in the state such as Perhentian, Kapas, and Redang islands, as well as Bidong Island, once a refuge to tens of thousands of Vietnamese refugees in the 1970s.

Kuala Terengganu (Malaysian pronunciation: [ˈkuˈala ˈtəˈrəŋˈganu] ; Terengganu Malay: Kole Tranung), colloquially referred to as KT, is the administrative, economic and royal city of the state of Terengganu, Malaysia. Kuala Terengganu is also the seat of Kuala Terengganu District. It is also the only royal capital among the nine royal states of the country to bear its state's name. Kuala Terengganu is located about 440 kilometres (270 mi) northeast of Kuala Lumpur on the East Coast of Peninsular Malaysia. The city is situated at the estuary of Terengganu River, facing the South China Sea.

As a district, Kuala Terengganu is the smallest in terms of area, but it and Kuala Nerus District that together form the city area has the largest population in Terengganu. The city population was 406,317 in 2010 and declined to 375,424 in 2020. City status was awarded to Kuala Terengganu with the title Bandaraya Warisan Pesisir Air (English: Waterfront Heritage City) on 1 January 2008.