Mr Hess has now assumed the role of managing director of the Americas region.
Mr Ford first joined Towers Watson 23 years ago and has since held a number of leadership roles.
Most recently he headed the company’s investment business in Europe, the Middle East and Africa.
Towers Watson managing director of risk and financial services Tricia Guinn said Mr Ford is well placed to succeed Mr Hess.
“Chris has proven himself to be very capable, both strategically and operationally, at propelling the business forward and delivering strong growth and excellent results for our clients,” said Ms Guinn.
Towers Watson’s investment business aims to generate financial value for institutional investors through risk management, asset allocation, fiduciary management and investment manager selection.
The company has around 800 associates globally, assets under advisory of more than US$2 trillion and around US$60 billion assets under management.