Westpac's head of business integration Jayne Opperman will leave the bank and Australia to become the new head of technology across APAC and EMEA for Citi.
Citi has been searching for a new technology executive to lead its 17 markets in the two regions since July this year.
It appears the role was previously filled by Shamus Weiland, who moved to the US to become the managing director for Citi's North American consumer technology group.
Citi's global head of product development for consumer tech, Sanjeev Mehra, had filled in while the bank searched for a replacement.
Opperman will join Citi in January and will relocate from Sydney to Singapore.
Her immediate task will be to "refine" the technology strategy for the APAC and EMEA regions.
"She will also evolve approaches that accelerate progress against each of our five priorities and work closely with each line of business to ensure our continued success as the region’s best digital bank," the bank said.
Opperman was lured to Westpac by chief information officer Dave Curran in mid 2015 to take on the business integration role as part of his new executive team.
It has seen her work on one of the largest technology transformations Westpac has undertaken in its history; the rebuild of its operations from the middle out through a so-called 'customer service hub'.
Prior to joining Westpac Opperman worked at the likes of the Commonwealth Bank, Lloyd's in the UK and more recently ANZ Bank. She has also worked at advisory firms KPMG and Pricewaterhouse Coopers.