McCahill will be responsible for all major international reward projects.
She has joined Dixons after one year as HR manager at Samsung’s Cambridge Solution Centre, where she managed global reward.
She previously held various roles at CSR, including talent and succession manager, and global reward specialist, when she was responsible for global reward in 15 countries.
Platt has joined Dixons from Philips, where her roles since 2000 have included HR manager, and reward manager, UK and Ireland.
Her other previous roles include HR business partner at Unisys and HR assistant at IBM UK.