In a statement to the ASX, CBA announced that Wendy Stops would become a director of the board effective immediately.
Prior to joining CBA, Ms Stops was senior managing director of technology, Asia Pacific, at Accenture.
"Ms Stops is an experienced, senior management executive in the information technology and consulting sectors," the statement said.
"[She] has had a global career that has seen her work and live in countries including Malaysia, Singapore and the USA,” it said.
CBA chair David Turner said Ms Kay, who has been a director of the bank since March 2003, will resign from her role effective 31 March 2015.
“[Ms Kay] has been a member of various board committees including risk, remuneration and audit committees,” the CBA statement said.
“As a former banker, lawyer and experienced company director, Ms Kay has been highly regarded for her expertise in the finance sector and experience across a broad range of industries and geographies."