The hat, made from beaver fur, was found wedged inside the attic fireplace in a Georgian farmhouse in South Derbyshire.
Experts explained these hats were "lucky items" placed in chimney breasts as far back as the 16th Century to "ward off evil spirits".
The hat is expected to fetch between £40 and £60 in the sale next month.
More news and updates from Derbyshire
Charles Hanson, manager of Derbyshire-based Hansons Auctioneers and Valuers, said: "Often in chimneys or very old properties you do find lucky items that were placed in chimney breasts to ward off evil spirits, like dead cats or objects.
"It would have maybe been on the high street as the latest fashion in Derby, down Sadler Gate in the 1790s, and it's just a really interesting find.
"Who knows, it might only make £20, it could make £100. It is sadly very tired."
The hat would have been worn by members of the upper class, and this type of hat also became part of uniforms donned by policemen and postmen, according to the antiques expert.
It is unclear how long the top hat has been in the fireplace of the home, located just outside Repton.
The hat will be entered into Hansons' textiles auction on 22 February.
A 200-year-old top hat is set to go under the hammer after being discovered in a fireplace.