Zenica (/ˈzɛnɪtsə/ ZEN-it-sə; Bosnian pronunciation: [zěnitsa] ^ⓘ) is a city in Bosnia and Herzegovina and an administrative and economic center of the Federation of Bosnia and Herzegovina's Zenica-Doboj Canton. It is located in the Bosna river valley, about 70 km (43 mi) north of Sarajevo. The city is known for its Ironworks Zenica factory but also as a significant university center. According to the 2013 census, the settlement of Zenica itself counts 70,553 citizens and the administrative area 110,663, making it the nation's fourth-largest city.

The urban part of today's city was formed in several phases, including Neolithic, Illyrian, the Roman Municipium of Bistua Nuova (2nd–4th century; old name of the city), with an early Christian dual basilica. Traces of an ancient settlement have been found here as well; villa rustica, thermae, a temple, and other buildings were also present. Earliest findings in the place date from the period 3000–2000 BC; they were found in the localities of Drivuša and Gradišće. Zenica's current name was first mentioned in 1415. A medieval church has been unearthed in Zenica, as well as the Franciscan Monastery of St. Mary. The independence of Medieval Bosnia is directly connected to Zenica (Gradješa's plate and abjuration act; Kulin ban's time; Vranduk, a castle of the Bosnian kings; Janjići and 'hižas' [homes] of Bosnian Church members; stećci, stone tombstone monuments, etc.) During Ottoman rule (1463–1878), Zenica became a Muslim town; at the end of the 17th century, Zenica had 2,000 citizens, mostly Muslims; Orthodox and Catholic Christians are mentioned again from the end of the 18th century, and Jews in the 19th century. Modern Zenica was mostly built in the Austro-Hungarian and Yugoslavian periods. The population rose rapidly during the 20th century, and from the Bosnian War until 2013, the city lost a quarter of its population. The municipality of Zenica became the City of Zenica in 2014.

The city is geographically located in the heart of Bosnia. The settled area is 43.01 km² (16.61 sq mi) and of the city proper covers 558.5 km² (215.6 sq mi). Elevation is 310–350 m (1,017–1,148 ft). The rivers Bosna, Lašva, Babina, and Kočeva flow through the settlement. A moderate continental climate prevails. The city has thirteen urban local settlements and it consists of a total of 81 rural settlements.

Zenica has nine national monuments. The football club Čelik is a landmark of the city, and it also has one of the tallest buildings in Bosnia and Herzegovina—Lamela. Famous Zenicans include Semir Osmanagić, Anabela Basalo, Danis Tanović, Amar Jašarspahić Gile, Mladen Krstajić, Dejan Lovren, Mervana Jugić-Salkić, and Amel Tuka.

There are several theories about the origins of name Zenica.

According to orally transmitted tradition, the city was named after the pupil of the eye (Ekavian Bosnian: zenica – pupil). There is also a legend that Zenica's name is derived from when Queen Katarina Kosača Kotromanić, who was leaving Bobovac during the Ottoman conquest of Bosnia in 1463, said "My pupil is left behind!" (Bosnian: Osta moja z[j]enica!). Because of its location in the center of Zenica field, the city is indeed analogous to the eye's pupil.

The name of the city can also be derived from the word zenit, meaning zenith, because it is in the center of Bosnia and Herzegovina.

The urban part of today's Zenica formed through several phases, which chronologically include a Neolithic community, the Illyrian 'gradina', the Roman Municipium of Bistua Nuova, and a Christian era-community.