Raja Sir Harnam Singh, KCIE (15 November 1851 – 20 May 1930) was the second son of Raja Sir Randhar Singh Bahadur, GCSI, Raja of Kapurthala and younger brother of Raja Karak Singh Bahadur, Raja of Kapurthala.
Harnam Singh was made Harnam Singh a hereditary Raja by the British Government 1907 for public service, awarded a Knighthood, KCSI, gave administration of his Awadh properties for his lifetime, a move which was objected by Jagatjit Singh but in vain.
Although raised a Sikh from birth, Sir Harnam later became a pious Christian and missionary, eventually becoming President of the National Missionary Society of India.
In 1875, he married Rani Kaur Sahiba, and had eight children, seven sons and one daughter:
Raja Harnam Singh held many dignities in his life. He was a member of the Legislative Council for the Punjab from 1900–1902, a Member of the Kapurthala Council of State and an honorary Fellow of Panjab University. He was appointed a CIE in 1885 and knighted with the KCIE in 1898. In 1907, Harnam Singh was given the personal title of Raja (roughly equivalent to the modern British life peerage) and was made a hereditary Raja in 1911, thus enabling him to found a separate branch of the Ahluwalia dynasty.
Harnam Singh died in 1930 at the age of 78, and was succeeded in his title by his eldest son, Raghubir Singh, who himself died two years later without issue. whereupon the title devolved upon his second surviving son, Raja Maharaj Singh. The line of Maharaj Singh maintains the title to this day.