The incomplete silver Polden Hill type brooch was found by a metal detectorist on land near Wem in December last year and may now go on display in the county.
John Ellery, the coroner for Shropshire, Telford and Wrekin, declared the find treasure at an inquest held in Shirehall today.
The brooch dates from the late 1st and early 2nd centuries - AD 80 to AD 140 - and is T-shaped with semi-circular wings that hold a recessed spring.
David Dickinson, who has been a metal detectorist for 40 years and is from near Wrexham, must now wait to find out how much the treasure is worth.
He said: "We were on an organised rally and there were quite a number attending when I found the brooch.
"This is the fourth treasure inquest I have been to, they were all declared treasure.
"I've also found a haul of coins just outside Cheshire before, over the years we've found some interesting things."
Brooches were used by the Romans to hold layers of clothes together and, although silver brooches are rare, hundreds of copper or bronze brooches have been found in the West Midlands.
Many of them are thought to have been made in the Severn Valley for the local population.
It is the third silver brooch of this type to have been found in Shropshire, with one from Albrighton now in Shrewsbury Museum and Art Gallery and another from Cleobury Mortimer part of the British Museum’s collection.
Shropshire Museums is now hoping to acquire the brooch and put it on display alongside the one found in Albrighton at Shrewsbury's museum in The Square.
Analysis at the British Museum showed the 31mm by 24.5mm brooch is around 40 per cent silver, mixed with copper, tin, lead and zinc
Now the find has been officially declared treasure, it will be valued by the Government's Treasure Valuation Committee and the museum will be allowed a grace period to raise the relevant funds.
Any money will be split between the owner and landowner as a reward.