The company became the first retailer to sign up for the Face Equity at Work Campaign, run by charity Changing Faces.
It joins companies including Shell, the Olympic Delivery Authority, Barclays and British Airways in its commitment to treat employees as well as customers with disfigurements equally and fairly.
The pledge requires Marks & Spencer to become aware of the causes and effects of disfigurement and commit to positive thinking on the condition, reflecting this in its policies and procedures.
According to Changing Faces, 90% of people subconsciously behave negatively towards people with disfigurements, causing them to be marginalised socially and professionally.
Tanith Dodge, director of HR at Marks & Spencer, said: "Great service is at the heart of our values and has been for 125 years. With 21 million customers coming through our doors each week, they trust us to do the right thing and treat them with respect, regardless of who they are or how they look. The same goes for our 72,000 staff."
M&S joins campaign to root out discrimination against staff with disfigurements
Marks & Spencer has pledged to address discrimination and prejudice in the workplace suffered by staff with facial disfigurements.
