Lam will take up the role of vice-president of commercial for Continental Europe, which is one of two key new positions and three senior appointments.
He will lead the integration of sales, marketing and revenue management across Continental Europe.
Christopher Hale, previously marketing director at Collinson Group, joins as the vice-president of marketing and commercial for EMEA.
Karin Nielsen, regional director of sales and marketing at IHG, has been appointed vice-president brand development and delivery across EMEA.
The team is headed by William Morris, senior vice-president of sales and marketing for EMEA.
Hale and Nielsen will report directly to Morris, while Lam will have a dual report to Morris and Robin Wicks, chief operations officer for Continental Europe.
IHG is one of the world's largest hotel groups, by number of rooms. It owns, manages, leases or franchises, through various subsidiaries, over 3,800 hotels and more than 571,000 guest rooms in nearly 100 countries and territories around the world.
IHG brands include InterContinental Hotels & Resorts, Crowne Plaza Hotels & Resorts, Holiday Inn Hotels and Resorts and Holiday Inn Express.