Fasel, who will start the new role in September, joins the five-star property from the InterContinental London Park Lane, where he has been general manager for four years.
He previously worked at hotels around the world, including Badrutt's Palace hotel in St Moritz, Switzerland, where he was managing director, and five years with the Shangri-La Group.
Fasel said becoming the general manager of the "iconic" Dorchester hotel was a "dream come true".
"I am looking forward to working with the management team to continue to be the number one choice for guests, create a dynamic environment for staff, and to ensure a profitable investment for our owners," he said.
Cowdray added: "Fasel is an outstanding manager and brings with him a wealth of experience of running international hotels. I am sure that his leadership qualities and passionate commitment to the role will achieve great success."
The Dorchester Collection currently has five properties in its portfolio - in London, Milan, Beverly Hills and two in Paris. The company last year announced it would look to expand in North America, European cities such as Madrid, as well as resorts and less-developed Middle Eastern destinations such as Qatar.
By Kerstin Kühn
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