| HH Maharaja Sir Jai Singh | |
| Maharaja of Alwar | |
| Reign: | 1892 to 1937 |
| Coronation: | 3 June 1892 |
| Succession: | Ruler of Alwar |
| Predecessor: | Mangal Singh Prabhakar |
| Successor: | Tej Singh Prabhakar |
| Spouse: | HH Maharaniji Sa Rathorji Shri Sugan Kanwarji d.of HH Umda-e-Raja-e-Buland Makan Maharajadhiraj Maharaja Sir Sardul Singh of Kishangarh State HH Maharaniji Sa Jhaliji Shri Jayendra Kanwarji Saheba of Dhuva in Wankaner State |
| Issue: | Maharajkumariji Baiji Lal Shri Taj Kanwarji Saheba m.to HH Maharaja Krishna Singh Ju Deo Lokendra Bahadur of Datia State |
| Royal House: | Naruka Kachwaha |
| Father: | Sir Mangal Singh Prabhakar Bahadur |
| Mother: | HH Maharaniji Sa Rathorji Shri Kishan Kanwarji Saheba d.of Maharaja Bhairon Singh of Ratlam State |
| Birth Date: | 14 June 1882 |
| Birth Place: | City Palace, Alwar, Alwar State, Rajputana |
| Death Place: | Paris, France |
Hon Colonel. HH Raj Rajeshwar Bharat Dharma Prabhakar Maharaja Shri Sawai Sir Jai Singhji Veerendra Shiromani Dev Bahadur (14 June 1882 – 19 May 1937), was the Naruka Kachwaha Rajput ruler of the Princely State of Alwar from the year 1892 to 1937. The only son of the previous ruler, Sir Mangal Singh Prabhakar Bahadur, Sir Jai Singh initially was noted as brilliant, erudite and charming. However, he was later forced into exile. He died in 1937 at the age of 54. He was succeeded by a distant relative, Tej Singh Prabhakar Bahadur.
He was educated in the prestigious Mayo College, Ajmer, in which his late father was the first to take admission. He was highly regarded an absolute Indian English orator and scholar. He assisted the farming community with the construction of a number of bunds (irrigation dams).[1]
Sir Jai Singh took pride in his State's infantry regiments and had them sent to China during the anti-Christian uprising in China and in the following relief operations. Alwar Lancers units served in the First World War. Recognising his services, he was appointed a Knight Grand Commander of the Order of the Indian Empire (GCIE) by the British in 1919.[2]
He features in the oil on canvas painting by Douglas Chandor, Prime Ministers of the Imperial Conference (October 1923).[3] [4]