Fictional livery of a navalised version of the AJS 37 for use aboard carriers

In 1968 the Swedish government ordered the development of a navalised version of the then still in development Saab 37 Viggen for use aboard its 4 aircraft carriers. The 37S would come in roughly the same versions as its land-based counterpart, but featuring folding wings, an arrestor hook, strengthened airframe, and deletion of the thrust reverser. Additionally, all variants of the 37S were fitted with the improved Volvo Flygmotor RM8B engine, which produced more thrust and far better surge margin.

The first version to enter service was, as with the air force model, the strike variant; the AJ37S. In the 1990's these were upgraded to AJS standard and served into the early 2000's, when upgraded JA 37DS block 3s replaced them in the strike role. Replaced just too early to take part in the Carolus Island conflict, the AJS 37S served as the vanguard against the Soviet Northern fleet for decades. The last versions to leave service were the JA 37DS and AJSF 37S photo recce version, eventually being replaced by the JAS 39ES Sea Gripen in 2026.