Junín Province is a province in northwestern Junín Region, in the central highlands of Peru. Its capital is the city of Junín.

The territory of the province is mountainous and it includes Lake Junin which is the largest lake entirely on Peruvian territory, and the second-largest lake in the country after Lake Titicaca. Some of the most important rivers are the Mantaro and the Ullkumayu (Ulcomayo).

The province borders the Tarma Province on the southeast, Yauli Province on the southwest, and the Pasco Region provinces of Pasco on the north and northwest, and Oxapampa on the northeast.

The Junín Province is divided into four districts (Spanish: distritos, singular: distrito), each of which is headed by a mayor (alcalde): The Junín Province is subdivided in four districts:

• Junín in the south
• Carhuamayo in the north
• Ondores in the west
• Ulcumayo in the east

Flooding caused by heavy rains has often caused river to overflow, triggering floods. Recent floods include those in 2019 and 2021.

• Antaqucha
• Allqaqucha
• Chacamarca Historical Sanctuary
• Chiqllaqucha
• Upamayu Dam
• Waqraqucha
• Yanaqucha

11°09′S 75°59′W / 11.150°S 75.983°W / -11.150; -75.983