According to the organisation, the new post holder will be responsible for the management of the governmentâs investments in the Royal Bank of Scotland (RBS) and Lloyds.
As part of his role, the ex-Bank of America (BofA) Merrill Lynch employee will also be responsible for drawing up a strategy for the sale of the shares.
He will replace John Crompton, another former BofA Merrill Lynch employee, who stepped down from the post earlier in the year.
Mr OâNeil said: âI look forward to engaging with Lloyds and RBS in UKFIâs critical role of representing the taxpayerâs interest as a shareholder in these institutions.
âDisposing of these stakes in an orderly manner will be among the most important events in the capital markets over the coming years. It is my intention to use all of my experience to protect and create value for the taxpayer from these investments.â
The new post holder spent 17 years working at the BofA Merrill Lynch with his most recent role as head of the International Corporate Finance and Restructuring Group.
By Jim Ottewill