Mr Trenholm, who has been NHS Blood and Transplant chief executive since 2014, has previously held senior local authority and civil service posts with the Royal Borough of Windsor and Maidenhead and the Department of Food and Rural Affairs (Defra).
He started his working life as an inspector with the Royal Hong Kong Police, and later worked with Surrey Police before moving to private sector roles.
CQC chair Peter Wyman said: 'I am delighted that CQC has been able to make such a strong appointment to the role of chief executive.
'His track record of delivering technological innovation at scale in order to deliver benefits for people was the deciding factor – given both CQC’s strategic focus on delivering an intelligence-driven approach to regulation, and the increasingly central role that technology has in transforming outcomes across the health and care system.'
Mr Trenholm said: 'I am really pleased to be joining the CQC at a time of challenge for both health and social care. I look forward to working with the CQC team to build on the strong foundations already in place, creating innovative methods of assuring safe and effective care for all.'
The CQC said that under outgoing chair Sir David Behan, it had become 'a catalyst for improvement, inspecting every hospital, adult social care provider and GP practice in the country'.
However, extensive analysis by GPonline of CQC practice ratings has called into question their fairness - revealing that factors outside practices' control such as funding and GP-patient ratios often appear heavily to influence the scores they receive.