SEI has appointed Diane Seymour-Williams as Board Chair of its European-based operation, SEI Investments (Europe) Limited (SIEL), while David Lawton has been appointed as an Independent Non-Executive Director at the business.
Seymour-Williams joined SIEL’s board in 2019 and steps into the Chair role following the retirement of Patrick Disney, who served as Chairman of the Board since 2019 and was the former head of SEI’s Institutional business in the EMEA region and responsible for launching SEI’s business in the UK. Board changes were effective in July 2025.
Seymour-Williams brings three decades of global investment experience, building businesses, structuring funds, and leading distribution and client relationship teams. She has held senior leadership roles as a portfolio manager, CIO, and CEO at firms that include Deutsche Asset Management and LGM Investments.
Seymour-Williams was also a founding partner of Acorn Capital Advisers, focused on advising families and family offices on manager selection and strategic asset allocation. She has chaired various investment, risk, and ESG committees and is a pro-bono member of the Investment Committees of Newnham College, Cambridge, and the Canal & River Trust.
Lawton brings 40 years of experience in financial services, regulatory, and public sector positions, including at the FCA and HM Treasury, and currently has a portfolio of non-executive roles across the financial services sector. He was previously Managing Director and Co-Head of the UK regulatory advisory services practice at Alvarez & Marsal.
At the FCA, Lawton was most recently responsible for markets and wholesale conduct policy, as well as leading the FCA’s European and International strategy, chairing several prominent international committees and representing the FCA at the European Securities and Markets Authority Board of Supervisors.
