Mr Parker will be responsible for Alcoa refineries across the world, including commercial and operational activities, environment, health and safety and the Refining Centre of Excellence.
He will also represent Alcoa in Australia, covering growth opportunities and co-ordinating government affairs, human resources, communications and associations.
Mr Parker joined Alcoa in 1994 and most recently served as vice-president Commercial, Alcoa Refining and director, Business Development and Marketing.
He formerly held roles in the US and Australia and holds a degree in International Business from Griffith University.
Alan Cransberg joined Alcoa in 1980 and served in domestic and international senior management roles.