Isfahan (Persian: اصفهان‎), historically also rendered in English as Ispahan, Sepahan, Esfahan or Hispahan, is the capital of Isfahan Province in Iran, located about 340 kilometres (211 miles) south of Tehran.

Isfahan is located on the main north–south and east–west routes crossing Iran, and was once one of the largest cities in the world. It flourished from 1050 to 1722, particularly in the 16th and 17th centuries under the Safavid dynasty, when it became the capital of Persia for the second time in its history. Even today, the city retains much of its past glory. It is famous for its Persian–Islamic architecture, with many beautiful boulevards, covered bridges, palaces, mosques, and minarets. This led to the Persian proverb "Esfahān nesf-e- jahān ast" (Isfahan is half of the world)

The Naghsh-e Jahan Square in Isfahan is one of the largest city squares in the world. It has been designated by UNESCO as a World Heritage Site. The city also has a wide variety of historic monuments and is known for the paintings, history and architecture.

Today Isfahan, the third largest city in Iran, produces fine carpets, textiles, steel, handicrafts, specific sweet and traditional delicious foods. Isfahan also has nuclear experimental reactors as well as facilities for producing nuclear fuel (UCF). Isfahan has one of the largest steel-producing facilities in the entire region, as well as facilities for producing special alloys. Mobarakeh Steel Company is the biggest steel producer in Middle East and Northern Africa and the biggest DRI producer in the world and Isfahan Steel Company is the first and largest manufacturer of constructional steel products in Iran.

The city has an international airport and a metro line.

Isfahan contains a major oil refinery and a large airforce base. HESA, Iran's most advanced aircraft manufacturing plant, is located nearby. Isfahan is also becoming an attraction for international investments, like investments in Isfahan City Center which constitutes the largest shopping mall in Iran and the fifth largest in the world.