Vernon worked at Accenture from 1969 to 2010. He was Managing Partner, EMEAI, 1989-2001 and International Chairman from 2001. From 2010 to 2016 he was Chair of the British Council. Until recently he has been a non-executive Director of FTI Consulting Inc. and Chair of Martin Randall Travel.

In parallel with these activities, he has had extensive involvement in the arts and in philanthropy. Vernon has chaired the boards of English National Opera (he continues as President), National Opera Studio, the Leeds International Piano Competition and Britten Pears Arts. He currently chairs Live Music Now.

He has long been interested in ways to increase levels of philanthropy in the UK. From 2015 to 2020 he led the Stop MS appeal which raised £50m for MS research. He is currently Chair of New Philanthropy for Arts and Culture - a major initiative to bring new philanthropy into arts and culture through its impact on health, education, wellbeing and the community. This has now come together with the Arts and Culture Fund (until recently, part of NESTA) to form Figurative, which will provide a range of services and finance to the arts sector including nurturing philanthropy to social investment.

In 2001 he established the Vernon Ellis Foundation to channel his personal giving. The focus now is on the social impact of the arts. Also, through his Foundation, he hosted around 80–90 concerts a year between 2005 and 2017 at his London home in support of musicians' and music organisations' development, and other fundraising events.

He was knighted for services to Music in 2011. He is a Fellow of the Royal College of Music and was given the ABO Award in 2014.