Executive leadership.

An executive leadership team comprising of the following members oversees the day-to-day operations and ongoing development of Defence Bank.


Marnie Fletcher.
B Com, B Arts, Post. Grad. Dip Applied Information Systems.
Acting Chief Executive Officer.
Mano Simos

Skills and experience.
Marnie is responsible for Defence Bank’s Frontline Branch and Lending teams as well as the Lending Operations, Member Operations, Member Direct and Member Care divisions. These teams have a direct line to our members and are the front face of Defence Bank. Marnie is also the sponsor of our Lending Journey Continuous Improvement Program.

Since joining in 2021, Marnie has led the transformation of Defence Bank’s Lending ecosystem and led the Member and Growth teams through a period of outstanding growth and innovation targeted at removing friction and simplifying the experience for our members and people.

Marnie has worked in the financial services sector for over 25 years, and whilst having worked with a broad spectrum of customers from institutional through to retail, her passion is for the everyday Australian and helping people create a better life through good financial decisions.

Dean Barton.
Chief Financial Officer.
Dean Barton

Skills and experience.
Dean joined Defence Bank as Chief Financial Officer in 2011. His primary responsibility is the bank’s financial and regulatory reporting, management reporting and budgeting, funding and capital management. He also acts as Company Secretary to Defence Bank.

Dean has more than 20 years’ local and international experience in financial roles including Financial Controller for ME Bank, and Asia-Pacific Regional Financial Controller for GMAC Financial Services.

Dean is a Fellow of CPA Australia and the Financial Services Institute of Australasia, and a graduate member of AICD. Dean holds a BCom from the University of Western Australia majoring in Accounting and Economics.


Kristen Bugeja.
Chief People Officer.
Kristen Bugeja

Skills and experience.
Kristen Bugeja leads the People & Capability team at Defence Bank. She has more than 20 years’ experience in the financial services sector.

Kristen has had extensive experience in delivering the cultural change that underpins Defence Bank’s business strategy. She has successfully driven change across a range of people functions including career development, talent and leadership programs, and employee engagement.

Under her guidance, Defence Bank was a finalist in the Australian HR Awards 2017 for ‘Best Change Management Strategy’ and in the Australian HR Awards 2016 for ‘Employer of Choice’.

Kristen is a certified member of the Australian HR Institute.


Sean O'Donnell.
MBA, B.Bus, Dip Fin Adv, GAICD
Chartered Banker
Chief Digital and Technology Officer.
Linda Craven

Skills and experience.
Sean joined Defence Bank as Chief Digital and Technology Officer in October 2023. He is an experienced senior executive and Non-Executive Director with extensive experience in the banking and technology sectors. He has held senior executive roles with global information technology firms. His banking career has seen him hold senior leadership roles in both major and regional banks.

In his current role Sean leads Defence Bank’s Business IT team. His team is focussed on enabling Defence Bank’s digital transformation with an emphasis on member experience, risk management and information security.

Sean strives to make a contribution to the wider community. He is an ambassador for Melbourne City Mission and its flagship fund raising event, Sleep at the ‘G. In addition he is an adjunct senior lecturer at Central Queensland University where he lectures on Banking and Finance as part of the University’s MBA programme.


Michael O'Reilly.
BA, Grad. Dip. Marketing.
Chief Marketing and Product Officer.
Michael O'Reilly

Skills and experience.
Michael joined Defence Bank as Executive Manager of Marketing in December 2017. He brings with him more than 22 years of product and marketing experience within the financial services sector.

Prior to joining Defence Bank, Michael was responsible for developing marketing strategies across a range of mutual and major financial institutions including Teachers Mutual Bank, Community First Credit Union, CommSec and Lloyds TSB. Michael’s experience also includes working abroad as a Product Manager for Lloyds TSB.

Michael leads the day-to-day marketing functions with specific responsibility for brand, marketing strategy and product.


Mano Simos.
BBus Accounting, Grad. Dip. Banking & Finance, GAICD.
Chief Risk Officer.
Mano Simos

Skills and experience.

Mano has been Chief Risk Officer at Defence Bank since October 2013. He is primarily responsible for the development and oversight of the bank’s Risk & Compliance Management Framework. Mano leads a team who collaborates with executives and their teams providing guidance and advice on the implementation of these frameworks. This second line function remains independent of the business and provides the Board and the Risk & Compliance Committee with assurance and insights around the management of our current and emerging bank-wide risks including credit risk oversight and financial crime.

Prior to joining Defence Bank, Mano worked at NAB - directly with the Business Banking CRO and with the Group Executive Business Banking as secretary to its Risk Committee and responsible for risk governance.

Mano is a graduate member of the AICD.