Louhajang River (Bengali: লৌহজং নদী, romanized: lauhajaṁ nadī [lowɦɔdʒɔŋ nɔdi]) is located in central Bangladesh.

It branches off from the Jamuna near Gabsain at Bhuapur, Tangail District.

It flows past Tangail city, Karotia and Jamurki before joining the Bangshi.

[3] The average depth of the Louhajang is 1 metre (3 ft) and maximum depth is 3 metres (9 ft).

[4] Encroachment on the river's banks has been a persistent problem for decades, with not just banana orchards and vegetable gardens, but also illegally constructed concrete structures having been built in many areas on both banks of the river.