Ludhiana is a city and a municipal corporation in Ludhiana district in the Indian state of Punjab. It is the largest city in the state, with an estimated population of 1,613,878 as per Census 2011.The population increases substantially during the harvesting season due to the migration of labourers from eastern states like Uttar Pradesh, Bihar, Odisha and Delhi. It has an area of about 3787 km². The city stands on the Sutlej River's old bank, 13 km south of its present course. It is a major industrial centre of northern India. Residents of the city may be referred to as Ludhianvis.

Ludhiana is located 100 km west from state capital Chandigarh on NH 95 and is centrally located on National Highway 1 from Indian capital New Delhi to Amritsar, and is well connected to New Delhi by road, frequent train service and by air. The land dips steeply to the North and the West, where prior to 1785 the river Sutlej used to run.

The Old Fort was situated at the banks of the Sutlej (and now houses The College of Textile Engineering) and legend has it that an underground tunnel connects it to the Fort in Phillaur - although why this should be is debatable, as the Sutlej was the traditional dividing line between the two principalities, often occupied by enemy forces.