An Explosive Ordnance Disposal (EOD) team arrived in Lerwick early on Saturday morning to deal with a suspected piece of ordnance.
A 50-metre cordon had been put in place at Hay’s Dock by the Lerwick coastguard and police after the item was found on the seabed there.
The bomb disposal team was dispatched from the Mainland on Friday.
A coastguard spokesman confirmed the site had now been made safe and reopened from 8.30am.
Shetland Amenity Trust also confirmed that its car park and access was back to normal.