General Stig Gustaf Eugén Synnergren (25 February 1915 – 29 April 2004) was a Swedish Army officer who was the Supreme Commander of the Swedish Armed Forces from 1970 to 1978. Synnergren was a strong advocate for the conscription system and during his time as Supreme Commander the combat aircraft Saab 37 Viggen was introduced. Synnergren was famous for advancing from the rank of captain to becoming the "youngest general in the modern times" in just five years.