Kielce (Polish: [ˈkʲɛlt͡sɛ] ^ⓘ; Yiddish: קעלץ, romanized: Keltz) is a city in south-central Poland. It is the capital of the Świętokrzyskie Voivodeship. In 2021, it had 192,468 inhabitants. The city is in the middle of the Świętokrzyskie Mountains (Holy Cross Mountains), on the banks of the Silnica River, in the northern part of the historical Polish province of Lesser Poland.

Kielce has a history back over 900 years, and the exact date that it was founded remains unknown. Kielce was once an important centre of limestone mining, and the vicinity is famous for its natural resources like copper, lead, uranium, and iron, which, over the centuries, were exploited on a large scale.

There are several fairs and exhibitions held in Kielce throughout the year. One of the city's most famous food products is Kielecki Mayonnaise, a type of mayonnaise.

The city and its surroundings are also known for their historic architecture, green spaces, and recreational areas like the Świętokrzyski National Park. In sports, the city is known as the home of the top-tier handball club, multiple Polish Champion, and one-time EHF Champions League winner Vive Kielce.

According to a local legend, Mieszko II Lambert, son of Boleslaus I of Poland, while hunting, stopped to rest and refresh, and fell asleep. During his sleep, he had a dream he was attacked by a band of brigands in a forest. In the dream he saw a vision of Saint Adalbert who drew a winding line which turned into a stream. When Mieszko woke up, he found the Silnica River whose waters helped him regain strength. He also discovered white tusks of an animal, perhaps wild boar. Mieszko announced he would build a town and a church to St. Adalbert at that site. According to this legend, the town's name Kielce commemorates the mysterious tusks (kieł in Polish). Various other legends exist to explain the name's origin. One states that the town was named after its founder who belonged to the noble family of Kiełcz, while another claims that it stems from the Celts who may have lived in the area in previous centuries. Other theories connect the town's name to occupational names relating to mud huts, iron tips for arrows and spears, or the production of tar (pkielce, a settlement of tar makers).

The most probable etymology traces the origins of the name to an Old Polish noun kielce (plural form of kielec 'sprout') and refers to plants sprouting in the wetlands where the settlement was located. The earliest extant document referring to the settlement by the name of Kielce dates to 1213.

The area of Kielce has been inhabited since at least the 5th century BC. Until the 6th or 7th century, the banks of the Silnica were inhabited by Celts. They were driven out by a Lechitic tribe of Vistulans who started hunting in the nearby huge forests and had settled most of the area now known as Lesser Poland and present-day Świętokrzyskie Voivodeship. The lands of Wiślanie were at first subdued by Bohemia, however they soon came under the control of the Piast dynasty and became a part of the emerging Polish state.

The area of the Holy Cross Mountains was almost unpopulated until the 11th century when the first hunters established permanent settlements at the outskirts of the mountains. They needed a place to trade furs and meat for grain and other necessary products, and so the market of Kielce was formed. In the early 12th century the new settlement became a property of the Bishops of Kraków, who built a wooden church and a manor. In 1171 a stone church was erected by bishop Gedeon Gryf. During the times of Wincenty Kadłubek a parochial school in Kielce was opened in 1229. By 1295 the town was granted city rights. In the mid-13th century the town was destroyed by the Mongol invasion of Ögedei Khan, but it quickly recovered.