Lieutenant General Sagat Singh, PVSM (14 July 1919 – 26 September 2001) was a General Officer in the Indian Army, notable for his participation in the annexation of Goa and later for his operational maneuver in crossing Meghna river and capturing Dhaka during Indo-Pakistani war of 1971. He held many commands and staff appointments throughout his career. He is regarded as one of the best Indian field Commanders to carry out operational maneuvers during any war.

Singh was born in a Rajput family in the village of Kusumdesar in Churu region of Bikaner State on 14 July 1919 to Brijlal Singh Rathore of Kusumdesar and a Bhati lady, Jadao Kanwar of Hadla. Brijlal was a soldier in the Bikaner Ganga Risala who served in Mesopotamia, Palestine and France during World War I. He was recalled to service at the outbreak of World War II and retired as an Honorary Captain. Sagat was the oldest of three brothers and six sisters, he completed his schooling from Walter Nobles High School at Bikaner in 1936.

Singh joined Dungar College at Bikaner but right after his intermediate exam in 1938, he was enrolled as a Naik in the Bikaner Ganga Risala. Later, he was promoted to Jemadar (now called Naib Subedar) and given command of a platoon.

With the outbreak of World War II, he was among the few Viceroy's Commissioned Officers who received a commission as Second Lieutenants in the Ganga Risala. The Risala was sent to Sind in 1941 to deal with the Hoor rebellion. Here, the Sadul Light Infantry replaced the Ganga Risala and Singh was transferred to the new unit. In 1941, the unit landed at Basra and came under the Iraqforce commanded by Lieutenant General Edward Quinan.

Singh, with the Sadul Light Infantry, then moved Jubair in Iraq. He was appointed the unit's Military Transport Officer after having obtained an instructor grading in the Military Transport Course. He later served as adjutant and then took command of a company. After a staff stint at the sub area headquarters, he was selected to attend the Middle East Staff College at Haifa. He was the only State Forces officer to be selected. After completing the staff course, he was appointed General Staff Officer Grade 3 (GSO III) at Headquarters 40th Indian Infantry Brigade in Ahvaz, Iran.

In September 1944, Singh rejoined his battalion and was appointed adjutant. He was selected to attend the Staff College, Quetta and joined the 12th War Staff course from May to November 1945. After completing the course, he was recalled to Bikaner and appointed brigade major of the state forces, working directly under the commander-in-chief. After the war, when it became apparent that India would be an independent nation, he was responsible for the absorption of the state forces into the Indian Army.

In 1949, Singh was transferred to the Indian Army and joined the 3rd Queen Alexandra's Own Gurkha Rifles. He was appointed General Staff Officer Grade 2 (GSO II) at Headquarters Delhi Area. His seniority in the state forces was restored and in October 1950, he was appointed brigade major (BM) of the 168 Infantry Brigade in Samba. During this stint, he attended the Mountain Warfare course and was shortlisted for command of the President's Bodyguard. After three years as BM, he was posted to the 3rd Battalion of the 3rd Gorkha Rifles as a company commander in October 1953. He served in the battalion for a year and-a-half in Bharatpur and in Dharamshala.

In February 1955, Singh was promoted to the rank of lieutenant colonel and appointed commanding officer of the second battalion 3rd Gorkha Rifles (2/3 GR) at Ferozepur. He moved the battalion to its field area in Jammu and Kashmir in October 1955 and relinquished command in December to attend the senior officers course. After completing the course, where he obtained an instructor grading, he took command of 3/3 GR at Dharamshala. In August 1957, he moved the battalion to Poonch and in November that year, he was posted as a senior instructor at the Infantry School Mhow.