No. 4 Squadron IAF (Oorials) is a fighter squadron of the Indian Air Force (IAF) equipped with the MiG-21 Bison, based at Uttarlai Air Force Station in Uttarlai in Barmer, Rajasthan, India. Since its establishment during the South-East Asian theatre of World War II, No. 4 Squadron remains the only fighter squadron other than No. 3 Squadron IAF and No. 7 Squadron IAF to remain continuously in existence in the service of India.