'Siegfried' (i) was the German seizure of the island of Hiiumaa (Dagö in German) off the coast of Estonia at much the same time as 'Beowulf' to take Saaremaa and Muhu (12/21 October 1941).

The primary object of the undertaking was to shield the western flank of Generaloberst Johannes Blaskowitz’s 18^th Army on the left of Generalfeldmarschall Wilhelm Ritter von Leeb’s Heeresgruppe 'Nord' as it advanced toward Leningrad after the launch of 'Barbarossa'.

Sub-plans involved in 'Siegfried' (i) were 'Siegfried Ost', 'Siegfried Mitte' and 'Siegfried West'. Generalmajor Werner Hühner’s 61^st Division was landed by assault boats, and by 16 October the Soviet forces had been ordered to evacuate the island, mostly to Odensholm and Hanko. Soviet resistance ended on 21 October at Cape Takhkona, yielding 3,388 Soviet prisoners.