Police and paramedics responded to reports of a collision on the A342 Monument Hill at around 10.10am on Saturday.
The man in his 60s from Melksham who was riding the motorcycle died after the crash.
A Wiltshire Police spokesperson said: ” His next of kin has been informed and our thoughts are with his family at this time.
“A road closure was put in place on the A342 between Upavon and Monument whilst the incident was dealt with and investigations were carried out.
“Any witnesses to the collision should call 101 and quote log number 114 of July 27.
“Alternatively, email SCIT@wiltshire.police.uk”
The driver of the other vehicle, a Citroen van, was uninjured.
The road remains closed in both directions from Marshall Road (Devizes) to the Etchilhampton turn-off as of 5.30pm on July 27.