The J35XS was part of a deal for Sweden to provide Finland with different variants of the J35 Draken. At first, only second-hand J35Fs, Bs, and Cs were provided with minor modifications, but Finland requested an upgraded variant of the J35F, more comparable to the J35J standard. Thus, the J35XS was conceived; it had better countermeasures, electronics, a better radar (though still very similar), more weapon pylons, and access to the RB24J (AIM-9P). A total of 12 aircraft were produced of this variant, and it was the only one assembled in Finland, while the kits were produced in Sweden by SAAB.

Introduced in Update "Apex Predators", the J35XS plays like all Drakens: fast and with good AoA capabilities. Of course, while performing manoeuvres it loses all of its speed, but it has a very interesting double delta wing design that allows the aircraft to retain energy at high speeds at the cost of agility. It has access to six RB24Js, which are just AIM-9Ps. This missile has decent range and acceleration, as well as 20Gs of pull. While these don't get you consistent destructions, they still perform decently when launched at unaware opponents. It also has access to 12 countermeasures; not a lot, however, being deployed one by one, they can last for a good time. While better than nothing, they are ultimately sub-optimal at best. This means that taking chaff is not recommended, and thus flying close to the ground to avoid radar locks is highly advised. Also, it uses an IRST coupled with its radar, which allows it to lock onto the heat signature of jets and slave the missile to that lock, but the locked target won't receive a warning unlike radar, which triggers the RWR if it’s able to detect the lock. The problem is that IRST can’t identify if the lock is friend or enemy, so watch out for friendly fire.