On 1^st November 1883 the 3^rd Engineer Regiment was constituted in Florence with 3 telegraphists companies, 2 sappers companies and a train company coming from the 1^st and the 2^nd Engineer Regiment. In 1895 the 3^rd Engineer Regiment became 3^rd Telegraphists Engineer Regiment composed by a General Staff, four sappers-telegraphists brigade and a specialists brigade (already detached in Rome since November 1894), three train and deposit companies. The Specialists Brigade became independent in 1909. In 1910 the brigades changed their names into battalions.

At the outbreak of the 1^st World War the regiment mobilized 24 telegraphists companies, 5 mobile militia companies and 1 train company. When the war ended, the trained telegraphists companies were 68. Guglielmo Marconi enlisted as volunteer and participated in the war as Officer of the 3^rd Telegraphist Engineer Regiment.

In 1919 the Regiment was dissolved to form the 1^st and 2^nd Radio Telegraphists Regiment, in view of the increasing employment of the radio-telegrapher means. In 1932 the two regiments were dissolved and absorbed by the Army Corps telegraphists battalions, as Army Corps signals battalions. At Forte Trionfale (headquarters of the 3^rd Regiment) a signals component still remained. During the 2^nd World War, in service for the 10^th Army Corps, the 10^th Connections Battalion operated, mobilized from the deposit of Santa Maria Capua Vetere. In 1940 the 10^th Marconisti Battalion was created and its command, along with the 131^st marconisti Company, was located in Forte Trionfale. After 8^th September the 10^th Marconisti Battalion was dissolved and reconstituted in Monteroni (LE) as Signals Battalion of SMRE operating by request of the General Staff until the end of the war.

In June 1947 the Signals Battalion of SMRE was named Special Connection Battalion of the War Ministry. In 1954 it changed its name into Special Signals Battalion of the Ministry of Army Defence and in 1975 into 10^th "Lanciano" Signals Battalion taking the traditions of the 3^rd Telegraphists Engineer Regiment; it maintained its headquarters in Rome and in 1976 it was given the War Flag by decree of 12^th November.

In 1993 the "Lanciano" Signals Battalion was changed into 3^rd Signals Regiment of the General Staff of the Army with the "Lanciano" Signals Battalion at its dependencies. On 1^st October 1997, in concomitance with the dissolution of the Signals Inspectorate, the Regiment passed in the logistic area of the Armed Force, at the dependencies of the C3 Department of the Logistic Inspectorate.

On 9^th September 1998, after the 43^rd Signals Regiment of Florence was dissolved, the "Abetone" Signals Battalion (FI), the 7^th Telecommunication Section (FI) and the 6^th Telecommunication Section (BO) passed at the dependencies of the 3^rd Signals Regiment.

On 1^st October 1998 the regiment passed in the operational area of the Armed Force, at the dependencies of the C4-IEW Command. On 1^st December 1998, after the reconfiguration of the 44^th Signals Regiment of Rome into 44^th TLC Support Regiment, it assumed at its dependencies other two companies, the 8^th TLC Section (Rome) and the 13^th TLC Section (PE). Later it also included the dissolved 47^th "Gennargentu" Signals Battalion.