National Highway 19 is a national highway in India. It was previously referred to as Delhi–Kolkata Road and is one of the busiest national highways in India. After renumbering of national highways, Delhi to Agra route is now national highway 44 and Agra to Kolkata route is numbered national highway 19. It constitutes a major portion of the historical Grand Trunk Road. It is also part of AH1 of Asian Highway Network, that traverses from Japan to Turkey.

The Grand Trunk Road is one of Asia's oldest and longest major roads. For at least 2,500 years it has linked Central Asia to the Indian subcontinent. It runs roughly 3,655 km (2,271 mi) from Teknaf, Bangladesh on the border with Myanmar west to Kabul, Afghanistan, passing through Chittagong and Dhaka in Bangladesh, Kolkata, Kanpur, Agra, Aligarh, Delhi, Amritsar in India, and Lahore, Gujrat, Rawalpindi, and Peshawar in Pakistan.