The second son of HH Maharaja Sir Sardar Singh of Jodhpur, he succeeded his elder brother Maharaja Sir Sumer Singh upon his untimely death to a disease in 1918; in 1922 he served as the aide-de-camp to the Prince of Wales (later King Edward VIII).

Ruling under the regency of his granduncle HH Maharaja Sir Pratap Singh of Idar State until 1923, he was then formally invested as Maharaja by Governor General Sir Lord Reading.

During his reign, Sir Umaid Singh reformed and reorganised the Jodhpur State Forces and the judicial department, introduced a scheme for extending primary education, revised the land revenue settlement and established state pensions and a Provident Fund for state employees.

Enjoying a distinguished military career, he died at his estate the Lake House on Mount Abu on 9 June 1947 after a progressive reign of 29 years, aged but 43.

He died from an acute attack of appendicitis while on a tiger hunt.