Welch starts in her new role on January 19, when she will become responsible for strengthening relationships with clients and will be based in Synovate's Singapore office.
Prior to her appointment, Welch was shopper research head at London-based 5one Retail Marketing. She has experience working at both agencies and clients.
Maz Amirahmadi, Synovate's executive director, said: "Pamela's appointment sharpens our focus and reflects our ongoing commitment to serving clients more effectively.
"I have no doubt that she is the right person to raise the bar when it comes to standards and quality in our business mix."