Kalba is a city in the Emirate of Sharjah in the United Arab Emirates (UAE). It is an exclave of Sharjah lying on the Gulf of Oman coast north of Oman. Khor Kalba (Kalba Creek), an important nature reserve and mangrove swamp, is located south of the town by the Omani border.
Kalba Mangrove reserve is open to the public and was developed as an eco-tourism resort by the Sharjah Investment and Development Authority (Shurooq). A number of conservationists and ecologists have expressed concern regarding the project.
Shell middens dating back to the fourth millennium BCE have been found at Kalba, as well as extensive remains of Umm Al Nar era settlement. An extensive and important assembly of petroglyphs lies to the south of Kalba at Khatm Melaha.
The town was captured by the Portuguese Empire in the 16th century and was referred to as Ghallah. It was part of a series of fortified cities that the Portuguese used to control access to the Persian Gulf and the Gulf of Oman, e.g. Khor Fakan, Muscat, Sohar, Seeb, Qurayyat, Muttrah. Kalba Fort, today restored as a museum, is thought to have been constructed on Portuguese foundations.