The squadron goes by the motto "Steadfast" with the Shikra adopted as its mascot.

Based at Paya Lebar Air Base, 149 Squadron was inaugurated on 1 June 1985 as one of the RSAF's fighter squadrons operating in the interceptor role.

The squadron initially operated the supersonic F-5E/F Tiger II fighter aircraft, before converting to the improved F-5S/T Tiger-IIs fighter aircraft in the early 1990s, these were retrofitted with new state-of-the-art avionics giving the aircraft capability of carrying out both air-to-air and air-to-ground missions.

On 5 April 2010, the squadron was re-inaugurated by Defence Minister Teo Chee Hean in an RSAF ceremony at Paya Lebar Air Base, with the arrival of five F-15SG strike fighters flown back the week before from Mountain Home Air Force Base in the United States.

The squadron's logo is centered with the serial number on the base of the tail.