Tenet /ˈtɛnɪt/: a belief or principle that is held to be true by members of a group or organisation.
Our name
Tenet Advisory was founded by Lindsay O’Sullivan and is built on the belief that strategy and leadership only create impact when they are grounded in real experience and delivered with clarity, pragmatism and authenticity. Lindsay’s work is shaped by 25 years of leading organisations through growth, transition and transformation, often in highly regulated and complex environments. This lived experience informs how Tenet partners with leaders and why our approach focuses on what works in the real world rather than consulting theory.
Lindsay is driven by creating impact that lasts. Some call it legacy.
Creating this kind of impact requires generosity, pragmatism, and decisiveness.
Lindsay’s career has centred on helping organisations transform, grow and respond to the changing needs of their stakeholders. He has held C-Suite and non-executive roles in complex, regulated entities and has worked with boards, regulators, funders, and governments on issues that demand clarity, collaboration and strong judgment. His work spans strategy execution, growth, organisational culture and performance, governance, technology adoption, financial management, risk management, stakeholder management, capability uplift, customer experience, innovation, and digital transformation.
He is known for building trust quickly, creating alignment across leadership teams, simplifying complex environments, and empowering people so they can act with confidence.
This breadth of experience means he understand the pressures and trade offs that senior leaders face. He brings practical insight from the real challenges of growing, leading people, managing risk, working with stakeholders, delivering value, and shaping change that lasts.
Lindsay O’Sullivan
Tenet Advisory acknowledges the Traditional Custodians of the lands on which we live and work, and pays respect to Elders past and present.
We have benefited from the privilege of living and working on this land and we recognise the deep and ongoing connection of Aboriginal and Torres Strait Islander peoples to Country, and the importance of listening and learning as part of creating lasting impact.