LAHIṆĀ SIṄGH SANDHĀṄVĀLĪĀ (d. 1843), son of Amīr Siṅgh Sandhāṅvālīā, enjoyed at the court of Raṇjīt Siṅgh the title of "Ujjal Dīdār, Nirmal Buddh, Sardār i-bā-Waqār (Resplendent presence, pure of intellect, the Sardār with prestige marked) Sardār Lahiṇā Siṅgh Sandhāṅvālīā Bahādur." Like other collaterals of the Mahārājā, Lahiṇā Siṅgh was rich both in wealth and intrigue; he first became a partisan of the Ḍogrā faction at the court, but changed sides when Kaṅvar Nau Nihāl Siṅgh came to power. When Kaṅvar Nau Nihāl Siṅgh fell out with Col Wade, the British political agent at Ludhiāṇā, Lahiṇā Siṅgh was deputed along with Faqīr 'Azīz ud-Dīn to go to Shimlā in September 1839 to call on Lord Auckland and demand Wade's removal from Ludhiāṇā. During the struggle for power between Rāṇī Chand Kaur and Prince Sher Siṅgh, Lahiṇā Siṅgh, along with Atar Siṅgh and Ajīt Siṅgh, supported the former.

         The Sandhāṅvālīā continued their intrigues against their sovereign despite the latter's offers of conciliation. In March 1841, the Darbār intercepted a letter from Atar Siṅgh Sandhāṅvālīā, then in British territory, to Lahiṇā Siṅgh and Kehar Siṅgh Sandhāṅvālīā, both of whom commanded troops in Maṇḍī, to retire with their force to the south of the Sutlej. The troops, apprehending treachery on their part arrested both of them and brought them to Lahore where Mahārājā Sher Siṅgh kept them under surveillance. In January 1842, they were imprisoned under the orders of the Mahārājā and were set at liberty in September 1842 when he granted Atar Siṅgh Sandhāṅvālīā and Ajīt Siṅgh Sandhāṅvālīā amnesty and allowed them to return to the Punjab from the British territory where they had taken asylum.

         Lahiṇā Siṅgh Sandhāṅvālīā was one of the principal actors in the triple murder on 15 September 1843 which shook the kingdom of Lahore. On the morning of that fatal day, Lahiṇā Siṅgh and Ajīt Siṅgh rode out of their mansion with 150 horse and 300 footmen. Lahiṇā Siṅgh hid himself near the garden of Javālā Siṅgh, and Ajīt Siṅgh went forward to the Bārādarī of Shāh Bilāval, and shot Mahārājā Sher Siṅgh dead, pretending to show him the carbine he had received as a gift in Calcutta. The shot was the signal for Lahiṇā Siṅgh to rush with his troops into the garden where the young heir apparent, Kaṅvar Partāp Siṅgh, was engaged in a ceremony distributing alms and, despite the woeful entreaties of the prince, cut off his head with his sword.

         Lahiṇā Siṅgh fastened the severed head of Partāp Siṅgh to his saddle, and hastened to join his nephew, Ajīt Siṅgh. Both of them then proceeded towards the Fort, where, after finishing off Wazīr Dhiān Siṅgh, they proclaimed minor Duleep Siṅgh as the new Mahārājā and Ajīt Siṅgh Sandhāṅvālīā as his Wazīr. The Khālsā army were aroused to anger and, led by Hīrā Siṅgh, son of Wazīr Dhiān Siṅgh they stormed the Fort early next morning (16 September 1843). Ajīt Siṅgh was shot dead while attempting to escape by lowering himself by a rope from the Fort ramparts. Lahiṇā Siṅgh, who had hidden himself in a vault, was seized and gored to death. His mutilated body was, at Hīrā Siṅgh's orders, fastened to a rope and dragged through the streets of Lahore. Later, it was quartered and pieces of flesh were hung on the gates of the city.