The menswear retailer revealed Cresco founder Tony Bogod has also been hired as a non-executive, both with immediate effect.
Moss Bros chairman Keith Hamill said: 'These appointments will help us drive the business both organically and through strategic development and thereby increase value for all shareholders.'
The retailer said like-for-like retail sales were flat in the first 16 weeks of the year, with group like-for-likes down 0.8 per cent. This compares with a retail like-for-like decrease of 0.9 per cent and a sales decline of 1.4 per cent in the first 10 weeks of the year.
Separately, Icelandic retail giant Baugur revealed that McCarthy has been appointed as non-executive director of the board. He has also accepted board positions in the group's Danish department store investments Magasin du Nord and Illum.