Kaithal, city, north-central Haryana state, northwestern India. It lies about 35 miles (55 km) west-northwest of Karnal.
Kaithal is said to have been founded by Yudhisthira, a Pandava king in the ancient epic poem Mahabharata, and it was later a Muslim cultural centre. Of historical interest are the large bathing tank (reservoir) and tombs of several saints dating from the 13th century ce. An agricultural market centre, it was constituted a municipality in 1867.
Industries include cotton ginning, saltpeter refining, and metalwork, pottery, and lacquered woodwork manufacture. Kaithal houses several colleges affiliated with Kurukshetra University in Kurukshetra to the northeast. Pop. (2001) 117,285; (2011) 144,915.