Sirte, also spelled Sirt, Surt, Sert or Syrte, is a city in Libya. It is located south of the Gulf of Sirte, between Tripoli and Benghazi. It is famously known for its battles, ethnic groups, and loyalty to Muammar Gaddafi. Due to developments in the First Libyan Civil War, it was briefly the capital of Libya as Tripoli's successor after the Fall of Tripoli from 1 September to 20 October 2011. The settlement was established in the early 20th century by the Italians, at the site of a 19th-century fortress built by the Ottomans. It grew into a city after World War II.

The Gulf of Sidra (Arabic: خليج السدرة, romanized: Khalij as-Sidra, also known as the Gulf of Sirte (Arabic: خليج سرت, romanized: Khalij Surt, is a body of water in the Mediterranean Sea on the northern coast of Libya, named after the oil port of Sidra or the city of Sirte. It was also historically known as the Great Sirte or Greater Syrtis.