The Su-9's fuselage and tail surfaces resembled those of the Su-7, but unlike the swept wing of that aircraft, the "Fishpot" used a 53° delta wing with conventional slab tailplanes.
The Su-9 had primitive R1L (NATO reporting name "High Fix") radar in the shock cone and was armed with four K-5 (AA-1 "Alkali") beam-riding air-to-air missiles.