7 SAI was established on October 1, 1973 at Bourke's Luck, Eastern Transvaal (Mpumalanga) by Commandant Eddie Webb. The first national servicemen began training in 1974. The unit would relocate to Phalaborwa in 1981.
In 1983 the Units Bravo Coy was stationed at Rundu for Reaction Force Duties under the command of 202Bn for 6 months, were after they were posted to Nepara for a further 6-month deployment. In its deployment at Sector 10 7 SAI Bravo Company was involved in operations in Angola were some members were wounded in an incident involving a Soviet-made hand grenade during Ops Askari.
The 1987 August intake of 7 SAI Alpha Company, was deployed to the operational area of Cuito Cuanavale, Angola in 1988 under the command of Captain Butler. Alpha Company consisted of five infantry platoons as well as an 81 mm (3.2 in) mortar platoon and was deployed to the eastern side of the Cuito river (a tributary of the Okavango River) for a period of 1 month. Alpha company flew from Rundu airport, landing at Mavinga and was driven in vehicles to its operational deployment areas. During its time of deployment, various platoons were allocated as mechanised infantry (in Ratels) while the remainder formed a base camp sending out roving patrols in the area.
After one month of 7 SAI's deployment in Angola, peace accords were signed and Alpha Company, 7 SAI, was withdrawn from Angola to a base camp in Rundu, South West Africa. Notable mention should be made of the efforts of Corporal Beukes, Mortar Platoon fire team leader, during this withdrawal. Beukes was a skilled mechanic and performed incredible work in the Cuito battle area repairing disabled Ratel fighting vehicles and performing vehicle maintenance duties during the company's withdrawal. Beukes ensured that the Alpha Company, 7 SAI column of vehicles was able to drive 600 km from Cuito to Rundu without a loss of a vehicle.
In 1989, during the UNTAG deployment in South West Africa/Namibia, Alpha Company provided base defence for the town of Oshakati with some of its platoons participating in the various counter insurgency operations against the PLAN infiltration that occurred during this time.
7 SAI changed from a training unit to a rear area protection unit when 113 SAI became part of the unit. It became part of the Rapid Deployment Force during November 1994, and it was placed under the command of the South African Army Infantry Formation as a motorised infantry unit in 2002.
7 SAI took part in Operation Boleas in 1998 in Lesotho to restore order after an army coup.
In 2002, the unit took part in the UN/AU peace mission, Operation Fibre to restore stability in Burundi.
SANDF’s Motorised Infantry is transported mostly by Samil trucks, Mamba APC’s or other un-protected motor vehicles. Samil 20,50 and 100 trucks transport soldiers, towing guns, and carrying equipment and supplies. Samil trucks are all-wheel drive, in order to have vehicles that function reliably in extremes of weather and terrain. Motorised infantry have an advantage in mobility allowing them to move to critical sectors of the battlefield faster, allowing better response to enemy movements, as well as the ability to outmaneuver the enemy.
The units emblem is a rooikat superimposed on a Maltese cross, which is in memory of two gold crosses commissioned by the ZAR President TF Burger and presented to two Bourkes Luck ladies for their help in caring for and nursing wounded Boer commandos during the Sekhukhune War.