[2] He was Chairman of the National Association of Youth Clubs (1973-1981), Intermediate Technology Development Group (1983-1990), the Trustees of the Tate Gallery (1988-1998), Aerfi (formerly GPA, 1993-1999), Pearson (1997-2005), HBOS (formerly Halifax Plc, 1999-2008), the House of Lords Appointments Commission (2001-2008), and Aldeburgh Music (2002-2012).

[3] Stevenson is a long time campaigner for greater understanding and treatment of mental illness informed by his own experiences of depression.

He is currently a trustee of Inter Mediate[6] which facilitates negotiation to help bring a sustainable peace in the most difficult, complex and dangerous conflicts where other organisations are unable to operate.

After the collapse of Lehman Brothers in September 2008 and the subsequent forced rescue-merger between HBOS and Lloyds TSB, Stevenson and Andy Hornby resigned, waiving their rights to any "pay-offs".

[11] In April 2013, the Parliamentary Commission on Banking Standards assigned the primary responsibility for the collapse of HBOS to Stevenson along with former chief executives Sir James Crosby and Andy Hornby.