An all-faith prayer was held and a coconut broken to mark the induction of Tejas today.
The No 18 Squadron, formed in 1965 with the motto "Teevra aur Nirbhaya" meaning "Swift and Fearless," was earlier flying MiG 27 aircraft.
The Squadron "actively participated" in the 1971 war with Pakistan.
The Squadron was "resurrected" on April 1 this year at Sulur.
Tejas is equipped with fly-by-wire flight control system, integrated digital avionics and multimode radar, while its structure is made of composite material.
It is also the "lightest and smallest" in its group of fourth generation supersonic combat aircraft," a Defence
release on Monday said.