William G. Parrett is an American businessman and senior manager who has served public, private, governmental, and state-owned clients worldwide. In October 2008, Parrett was elected to the board of directors of UBS AG and, in November 2014, to the Board of Directors of UBS Group AG. In May 2018, he stepped down from this role and was focussing on the position of President of UBS Americas Holding LLC.

Deloitte Touche Tohmatsu Limited, commonly referred to as Deloitte, is a British multinational professional services network. Deloitte is the largest professional services network by revenue and number of employees in the world and is considered one of the Big Four accounting firms, along with EY, KPMG, and PwC.