He was born in 1860 at Sarhali, district Amritsar of the Punjab. His grandfather, Rattan Singh was a high-ranking military officer in the Khalsa Army and had fought against the British during the Anglo-Sikh Wars and he declined the British offer of a jagir after the annexation of the Punjab. Later on, His father Hukam Singh went to Malaya where he settled down as a contractor. Gurdit Singh received little education in his childhood. Due the harsh treatment of his teacher and left the school. However, at the age of 13 he privately acquired elementary education so as to be able to correspond with his father in Malaya.
Gurdit Singh visited Malaya in about 1885 and conducted business in Singapore and Malaya as a contractor. He returned from there in 1909. In 1911 he raised his voice against forced labour. He wrote to the Government complaining against officials who forced poor villagers to work for them without remuneration, and when he received no response, he exhorted the people of his village to refuse to be subjected to begar (forced labour).
He chartered a Japanese ship, Kamagata Maru in 1914 to go to Canada where the government had put restrictions on the entry of Indians. The ship, renamed as Guru Nanak Jahaj, had a total of 372 passengers out of whom 351 were Sikhs and 21 Punjabi Muslims. The ship sailed from Hong Kong to Vancouver on April 3, 1914. The obstructions put up by the alien authorities and the hardships faced by its passengers turned them into staunch nationalists. The ship reached Vancouver on May 22, 1914 and it was not allowed to anchor and was attacked by the police at night. The attack was repulsed by the passengers and it created a great stir among the Indians in Canada.
An agreement was reached and the ship sailed back to India. It reached Calcutta on September 29, 1914. However, the passengers were not allowed to enter Calcutta, they were rather ordered to board a Punjab-bound train especially arranged for the purpose. They refused to do and many of the passengers were shot dead, a great many escaped. Baba Gurdit Singh escaped and remained underground for may years till in 1920 on the advice of Mahatma Gandhi he made a voluntary surrender at Nankana Sahib and was imprisoned for five years. After his release he settled down at Calcutta where he died on 24 July, 1954.