| Department of Casanare | |
| Native Name: | Departamento de Casanare |
| Native Name Lang: | es |
| Type: | Department |
| Image Map1: | Casanare Topographic 2.png |
| Map Caption1: | Topography of the department |
| Motto: | Trabajo y Libertad (Spanish: Work and Freedom) |
| Anthem: | Himno de Casanare |
| Coordinates: | 5.35°N -72.41°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Colombia |
| Subdivision Type1: | Region |
| Subdivision Name1: | Orinoquía Region |
| Parts Type: | Largest city |
| Parts Style: | para |
| Established Title: | Established |
| Established Date: | July 4, 1991 |
| Blank Name Sec1: | Provinces |
| Blank1 Name Sec1: | Municipalities |
| Blank1 Info Sec1: | 19 |
| Seat Type: | Capital |
| Seat: | Yopal |
| Leader Title: | Governor |
| Leader Name: | Salomon Andres Sanabria (2020-2023) |
| Unit Pref: | Metric |
| Area Total Km2: | 44640 |
| Area Rank: | 10th |
| Elevation M: | 350 |
| Population Footnotes: | [1] |
| Population Total: | 420,504 |
| Population As Of: | 2018 |
| Population Rank: | 25th |
| Population Density Km2: | auto |
| Demographics Type1: | GDP |
| Demographics1 Title1: | Total |
| Demographics1 Info1: | COP 23,661 billion (US$ 5.6 billion) |
| Timezone1: | UTC-05 |
| Iso Code: | CO-CAS |
| Blank Name Sec2: | HDI (2019) |
| Blank Info Sec2: | 0.750[2] · 16th of 33 |
| Website: | www.casanare.gov.co |
Casanare (pronounced as /es/, Spanish; Castilian: Departamento de Casanare) is a department located in the central eastern of Colombia. It is famous for its oil and natural gas production as well as its livestock and extensive plains.[3] It is also the tenth largest department with an area of 44,490 km2, similar to that of Denmark, but also the seventh least densely populated. Its capital is Yopal, which is also the episcopal seat of the Roman Catholic Diocese of Yopal. It contains oil fields and an 800 km pipeline leading to the coastal port of Coveñas owned by BP.
The Upía River (Río Upía) is in Casanare.[4] Casanare, Ariporo, Guachiría, Guanapalo, Pauto, Tocaría, Cravo Sur, Cusiana, Túa y Upía.
A former subregion of Boyacá, Casanare became separate department in 1973.