Mentor list / Mentor bio
Overview
Sir John Manzoni currently serves as Chair of Diageo plc (appointed February 2025), Chair of SSE plc (since 2021), and Independent Director of KBR, Inc. He also advises Mace Ltd, bringing his governance expertise to the energy, infrastructure, and national security sectors. He also chaired the Atomic Weapons Establishment (AWE plc, 2021-2024).
His executive career spans senior roles at BP, including CEO of Refining & Marketing (2002-2007) and CEO of Gas & Power (2001-2002). In 2007, he became President & CEO of Talisman Energy (2007-2012), steering the business into shale gas and new markets.
In public service, Sir John was appointed CEO of the Major Projects Authority (2014), then made history as the first CEO of the UK Civil Service and Permanent Secretary to the Cabinet Office (2014-2020). He led a landmark transformation of Whitehall, enhancing transparency in delivery and central leadership capabilities.
He brings deep cross-sector expertise in:
• Governance of complex institutions – board leadership across energy, national infrastructure, defence, and consumer goods
• Energy & infrastructure strategy – executing large-scale refinery, gas, and energy operations and strategic capital reallocation
• Public sector transformation – leading cross-government reforms, functional modernisation, and a delivery-centric culture
• Crisis & risk oversight – managing legacy safety incidents, government projects, Brexit preparation, and national security mandates
Sir John trained in civil and petroleum engineering at Imperial College London, later earning an MSc in Management as a Sloan Fellow at Stanford. Knighted in 2020 for public service, he embodies disciplined execution, strategic clarity, and the rare ability to bridge industry, government, and institutional systems.
PDF Profile
download pdf profileMajor Career Roles
Diageo plc
Independent Chair
SSE plc
Chair
UK Department for Civil Service
CEO
KBR Inc.
Independent Non-Executive Director
Gas and Power
CEO
Other Career Highlights
Talisman Energy Inc.
President/CEO
Accenture UK Ltd
Adviser
SABMiller plc
Non-Executive Director
Leyshon Energy Ltd
Chair
Stanford Graduate School of Business
Advisory Board member
Major Projects Authority
CEO