A military commander and jagirdar of the Sikh Darbar was the son of Desa Singh Majithia and foster-brother of Lahina Singh Majithia. Details of his early career under Maharaja Ranjit Singh are scarce. British records, however, locate him as the governor of Hazara and the commander of Darbar troops in 1844. He was called to lead Sikh military operations against jasrota to forestall the machinations of Raja Gulab Singh Dogra of Jammu. General Sham Singh Atarivala and General Ratan Singh KIan followed separately the main Sikh army under Ranjodh Singh. The fortress was reduced and Gulab Singh obliged to surrender. The latter also made over to the Sikhs Raja Hira Singh's treasure brought from Lahore and hidden there.

With the withdrawal of Lahina Singh Majithia from Lahore to British territory in March 1844, the political influence of the Majithias had sunk low at the Darbar. Finding the fortunes of the family declining, Ranjodh Singh joined Jawahar Wigh's faction. In the first Anglo-Sikh war Ranjodh Singh commanded a division of the Khalsa army with 70 guns. He entered the Jalandhar Doab, and having joined his forces with the Ladva chief, seriously threatened Ludhiana. He had a skirmish at Baddoval, 11 km on the road to Jagraoh; with Maj-Gen Harry Smith, who had hastened to the relief of Ludhiana, on 21 January 1846. Outnumbered, the British general was chary of giving battle. He made a detour to the right, and hastily retreated towards Ludhiana. Ranjodh Singh's artillery opened up a cannonade on the retiring British force. A portion of it was worsted, with 77 men taken prisoner. General Smith was however able to save Ludhiana, but the Sikhs claimed a victory at Baddoval. Ranjodh Singh marched on jagraoh in order to cut off British communications with Firozpur. He took part in the battle of 'Alival on 28 January 1846. After the treaty of Bharoval, Ranjodh Singh was made a member of the Council of Regency. In 1848, he was arrested following interception of his correspondence with Diwan Mal Raj of Multan, but was released after the war. His jdgar was confiscated and he was given a pension of Rs 2,500 per annum.

Ranjodh Singh Majithia died in 1872.