A white Honda Civic left the road and hit a tree at around 7.50am.
Emergency service attended and the 87-year-old driver was pronounced dead at the scene.
The road was closed for around four hours while investigations were conducted at the scene.
Officers are now appealing for witnesses.
Sergeant Andy Gibb from Police Scotland’s Road Policing Unit said: “Our thoughts are with the family and friends of this man who has tragically lost his life as a result of the collision.
“I would ask anyone who was driving on the A7 between Hawick and Langholm and who saw the collision to come forward.
“I would also ask anyone who may have seen the white Honda Civic immediately prior to the collision to get in touch.
“Similarly anyone with any information relevant to the inquiry is asked to contact us as soon as possible.”
Those with information can contact Police Scotland on 101, quoting incident number 1169 of 29 April, or reports can be made anonymously through Crimestoppers on 0800 555 111.