Sri Lanka Sinha Regiment was the first rifle regiment of the Sri Lanka Army and was formed on 1 October 1956 at the Imperial camp at Diyatalawa. The first battalion primarily consisted of 60 officers and other ranks from the Ceylon Light Infantry with Lt Col R. D. Jayathilaka MBE as the first commanding officer.

The D company of the volunteer Ceylon Light Infantry was transformed into the Rajarata Rifles under the leadership of Lt Col (later Colonel) S.D. Ratwatte, and went on to become the 2nd Volunteer Battalion of the Sinha Regiment on 1 October 1956. On 1 October 1969 the 3rd Volunteer Battalion of the Sinha Regiment was formed at Hill School in Nuwara Eliya.

The regiment first saw action during the 1971 Insurrection and underwent an expansion with escalation of the Sri Lankan Civil War. With the expansion of the regiment the Regimental Centre of Sri Lanka Sinha Regiment was established on 9 May 1988 at Diyatalawa at the same location where the 1st Battalion of the Sinha Regiment was raised. Brig D Wijesingha was the first regimental commander. Later, on 21 October 1989 the Regimental Centre was relocated to Ambepussa Camp where the 1st Battalion of the Sinha Regiment was at that time. The regiment distinguished itself greatly during the Sri Lankan Civil War including having three Parama Weera Vibhushanaya and one Weerodara Vibhushanaya recipients. In 1990 the elements of the 6th Battalion successfully held the old Dutch fort of Jaffna for two months while surrounded and under siege until it was relieved by the subsequent Operation Thrividha Balaya. July 1991 the 6th Battalion garrisoned Elephant Pass base when it came under siege with the LTTE launching a massive attack on the base. The battalion held out what was termed the battle of all battles until it was relieved following Operation Balavegaya 18 days later.

On 3 May 2005 a contingent of troops from the regiment took part in the United Nations Stabilization Mission in Haiti.

The Sri Lanka Sinha Regiment is the only regiment in the history of the Sri Lanka Army to produce an army commander holding the rank of a full general (four star) and later a Field Marshal as indicated in the notable members area.

As a rifle regiment it marches in 180 steps a minute during parade when it is involved, together with the regimental band - the only Sri Lanka Army regiment to do so.

Commander Security Force (Wanni) Major General WPADW Nanayakkara RSP VSV USP ndu assumed duties as the 18th Colonel of the Regiment of the Sri Lanka Sinha Regiment on 01 January 2024. Brigadier CS Thibbotuge assumed duties as the 25th Commandant of the Regimental Centre Sri Lanka Sinha Regiment on 15 March 2023 during a charm ceremony held at the Regimental Centre, Ambepussa.

• Corporal Gamini Kularatne  †
• Captain Saliya Upul Aladeniya  †
• Lance-Corporal A. M. B. H. G. Abeyrathnebanda  †
• Sergeant A. M. Anura  †
• Lance Corporal K. G. M. Rajapaksha  †

• Captain (QM) P. L. S. L. Cooray - 1989
• Corporal R. P. R. Wickramapala - 1998

• Field Marshal Sarath Fonseka, RWP, RSP, VSV, USP, rcds,PSC - Former commanding officer of the Sri Lankan Army
• General Anuruddha Ratwatte - Former Cabinet Minister and Deputy Minister of Defence
• Major General A.R. Udugama, MBE - Former Commander of the Ceylon Army
• Major General MAM Dias RWP, RSP, VSV, USP ,PSC -Former General Officer Commanding, 54 Division in Mannar
• Major General E. G. Thevanayagam - former Chief of Staff, Sri Lanka Army
• Major General H.S Hapuarachchi, - Former Chief of Staff, Sri Lanka Army.
• Major General Gemunu Kulatunge, RSP, USP  † - Former Deputy Chief of Staff, Sri Lanka Army.
• Major General Kumudu Perera RWP RSP VSV USP ndu - Former Deputy chief of staff, Sri Lanka Army
• Major General Laksiri Waduge RWP RSP VSV USP ndu - Former Commander Security Forces Headquarters – Central
• Major General Susantha Mendis  † -Former Brigade Commander, 512 Brigade.
• Major General D.W. Hapuarachchi - Commanding Officer - 1st Bn SLSR, Founder Commanding Officer Sri Lanka National Guard
• Brigadier T.S.B. Sally - Commanding Officer - 1st Bn SLSR, Chief of Staff, Sri Lanka Army.
• Brigadier S.B. Miyanadeniya - Commanding Officer - 1st Bn SLSR, Director Training SL Army
• Major D.M.L.B.Dissanayake RSP - Commanding Officer - 15th Bn SLSR
• Staff Sergeant Pradeep Sanjaya, - Bronze medalist 400m London Paralympics 2012, 4th Battalion Sri Lanka Sinha Regiment.

• Sri Lanka Army

• Official website