The Fairy Queen, built in 1855, is the world's oldest steam locomotive in regular operation today, plying between New Delhi to Alwar in India (note that the oldest operable steam locomotive in existence currently is the John Bull, which was built in 1831; however, the John Bull is preserved in mostly static display). The locomotive was certified by the Guiness Book of World Records to be the oldest operational locomotive after the Rajasthan government invoked it in 2004 to lug a deluxe train in order to boost tourism in the area. The Fairy Queen is run on the lines of the Palace on Wheels, the internationally renowned train.

The Fairy Queen was constructed in Leeds, England in 1855, and reached Calcutta in 1895 where it was christened as the Fairy Queen. The locomotive was given its serial number 22, by its then owner, The East Indian Railway. It began to haul light mail trains between Howrah and Ranigunj , but was soon consigned to line construction duty in the state of Bihar, where it served until 1909.

The locomotive spent the next thirty-four years on a pedestal outside the Howrah Railway Station near Calcutta. In 1943, the locomotive was shifted to the Railway Zonal Training School at Chandausi, where it served as a curiosity object for many of the students based there. In 1972, the Indian government bequeathed the heritage status to the engine rendering it a national treasure. The locomotive was spruced up and given a special spot in the newly built Rail Transport Museum, Chanakyapuri, New Delhi.

On October 23, 2004, the Rajasthan government reintroduced the locomotive after the runaway success of the Palace on Wheels. The two-day excursion sees the train plying from New Delhi to Alwar to the Sariska Tiger Reserve . The train pulled by this locomotive can accommodate thirty-eight passengers and the ticket is priced at Rs. 7,500 for adults and Rs. 3,750 for children.