Son of Bhai Sundar Singh and Mai Uttam Kaur, was among those who fell martyrs at Nankana Sahib on 20 February 1921. The traditional occupation of the family was weaving, but Harnam Singh's father and grandfather took to peddling cloth. Harnam Singh was hardly five years old when the family migrated to and permanently settled as drapers at Shahkot, an upcoming market town in Sheikhupura district. He learnt Gurmukhi (Punjabi) at home and adopted tailoring as a profession.

In 1914, he was administered the vows of the Khalsa by a group headed by Bhai Mahitab Singh Bir. Harnam Singh got up a preaching outfit comprising, besides himself, his younger brothers, Bachan Singh and Dalip Singh, and went around spreading the Singh Sabha ideology, administering the rites of amrit and performing marriages in accordance with the Sikh ceremony of anand. He participated in the liberation of gurdwaras at Sialkot (Babe di Ber), Chuharkana (Khara Sauda) and Gojra. Finally, he was one of the five volunteers of Shahkot who led by Bhai Santa Singh joined the jatha of Bhai Lachhman Singh Dharovali for their march towards Gurdwara Janam Asthan, Nankana Sahib, where they attained martyrdom on 20 February 1921.

Source: Encyclopaedia of Sikhism, Harbans Singh