Based on the earlier Su-7 (so much that NATO retained the same code name), the Sukhoi Su-17 'Fitter' was one of the most successful ground-attack aircraft of the late Cold War period which has now boasted of almost four decades of service with many air forces around the world. The main difference with its predecessor was a variable-geometry swept-wing, the first major Soviet aircraft with one although its pivot is located midway along the span rather than the root. Another major change was a bulged dorsal spine which housed extra fuel necessary to address one of the Su-7's main deficiencies which was poor range. The Su-17 featured an increased emphasis on survivability and ruggedness which was greatly appreciated by its pilots, it was also optimized for shorter take-offs and landing given the possible need to disperse from major airfields in the event of nuclear war. The Su-17 could also be equipped with a formidable array of weaponry and gradually more advanced avionics including a laser designator and a nav/attack system as well as electronic countermeasures. This allowed it to be used for a variety of roles including SEAD and reconnaissance. Throughout its service life, the Su-17 has seen extensive combat most noticeably during the Soviet Afghanistan War where it had reliability levels exceeding that of all other attack aircraft and helicopters. It was also in action during the Iran-Iraq War, and various engagements with US forces over the Gulf of Sidra and in the Middle East. Russian aircraft were retired from service in the mid-2000s. Export clients of the Su-17 (where it is known as the Su-20 and Su-22) included most Warsaw Pact nations and Soviet allies and it is still in service with a handful of air forces including NATO member Poland as well as Syria where it has been used extensively during the ongoing civil war (notably, one was shot down in 2017 by a US F/A-18E).

First flight of the Su-7IG prototype (basically a Su-7 with different wings) was on 2 August 1966 and was given the NATO code name 'Fitter-B', the same as the intial production Su-17 that was built in small numbers (and exported as the Su-17K).The first major production version was the Su-17M 'Fitter-C' which also included a more powerful engine and more advanced avionics. This was later improved into the Su-17M2 'Fitter-D' with a terrain-avoidance radar and a laser rangefinder. A further avionics upgrade resulted in the Su-17M3 'Fitter-H' with an extra internal fuel tank and an additional weapons pylon on each wing. Finally, the definitive Su-17M4 'Fitter-K' increased the range of precision weapons at its disposal (including anti-radiation missiles) as well as a host of other avionics upgrades. Export versions of the Su-17 were designated Su-20 and were basically downgraded versions of the Su-17M. Other versions were based on Soviet models albeit with some changes, these were the Su-22 'Fitter-F' (Su-17M2 with a more powerful engine), the Su-22M3 'Fitter-J' (Su-17M3), the Su-22M4 (Su-17M4) and finally, the Su-22M5 with a joint Russian-French advanced cockpit design including a HUD, HOTAS controls and multifunction displays. Lastly, two-seater trainer variants include the Su-17UM2, Su-17UM3, Su-22U and Su-22UM3K 'Fitter-G' while a small number of reconnaissance conversions are designated Su-17R (Su-20R for export).