The first mention of this castle, enthroned atop a rocky spur above the River Töss, was in the year 1027. The original name of "Chuigeburg" (= cow castle) points towards a castle of refuge. After Hartmann von Dillingen acquired ownership of the property and the castle by marriage, he built up both and called himself Count of Kyburg after his new headquarters. His family became one of the most important noble lineages in the region covered by the present central Swiss plateau, alongside the Habsburgers and the Savoyards. Following the death of the last of the Kyburgers in 1264, Rudolf von Habsburg then secured the inheritance.
After he was elected to be King of Germany, the imperial regalia were even supposed to have been held at the castle.
Later on, the Habsburgers relocated their interests further to the east (Carinthia and Lower Austria); this led in the 15th century to the Earldom passing by purchase into the ownership of the City of Zurich, which administered it in the form of a bailiwick. From then until 1798, distinguished citizens of Zurich served 6-year terms as High Bailiff at Kyburg, holding court and collecting taxes.
Kyburg lost its administrative function as part of the reorganisation of 1831, and was auctioned off. The Polish Count von Sobansky spent his declining years here.