Paramedics were called to Bath Road in Colerne on Monday morning following reports that a man had fallen from a steamroller.
A Great Western Ambulance Service spokeswoman said the man was pronounced dead at the scene having suffered “traumatic injuries”.
The Health and Safety Executive has attended the site ahead of an inquiry.
In a statement to the BBC, Wiltshire Police said officers “attended a report of a seriously injured man following what appears to be an accident involving an industrial roller near to a farm in Bath Road, Colerne”.
“Sadly, the 56-year-old local man was deceased at the scene,” it added.
“His family have been informed but formal identification has not yet been completed.
“The Health and Safety Executive have been informed and inquiries to establish the circumstances surrounding the man’s death are ongoing.”