He joined Kia four years ago and was part of the successful launch team for the new cee'd, Cerato, Sportage and Picanto models.
Unwin previously worked at Daewoo Cars, part of the team responsible for the launch of Daewoo in 1995.
SsangYong UK managing director Paul Williams said: I believe that we need to be very focused in targeting particular market segments and users with SsangYong, and that will include taking the product to the customers rather than expecting them to come to us.
Nigel's experience of building brands and outside events is especially relevant.