O'Byrne sits on the Board of Centrica Plc, the leading energy supply and in-home servicing provider in the UK and Ireland. He has chaired the Audit and Risk Committee since May 2019 and is the Senior Independent Director (SID). O'Byrne sat on the board of Land Securities Group Plc, the UK's largest listed real estate group, for nine years where he chaired the Audit Committee and was SID.