The statue of the mythical beast has been lowered into place at a mausoleum at the Old Parish Church at Kinfauns, Perthshire.
Part of the church dates to the 12th Century with the site now being restored as part of a major heritage project.
The unicorn was originally built at the mausoleum , which still stands within the walls of the old ruined church, to reflect the coat of arms of a family buried there.
The unicorn also became the national animal of Scotland in the 1300s given it was the natural enemy of the lion - a symbol that the English royals adopted around a hundred years before.
The last unicorn at Kinfauns is believed to have been destroyed around 100 years ago with stone carver Michelle De Bruin working from old photographs to create a replica.
The sculptor was on-site yesterday (Tuesday) to see her the 3ft sandstone piece installed.
Ms De Bruin said: “I was really pleased to see it up on the building. Obviously, when you are carving it, the sculpture is on a banker on a table infront of you. It was good to see it in place where it should be.”
The Old Parish Church at Kinfauns, in the Carse of Gowrie to the east of Perth, was originally a chapel linked to Scone Abbey.
It was destroyed during the Reformation, rebuilt and then abandoned around 1857 with a larger replacement church built nearby.
Since then, the original has become overcome by thick ivy which restorers have cleared over the past two years.
The arrival of the unicorn is the latest step in the renovation of the old church, which is protected as a scheduled monument.
Although a church has stood on the site since the 12th Century, part of what remains dates from the 15th and 16th Century.
The work has been funded by Tay LP, Perth and Kinross Heritage Trust and Historic Environment Scotland.