'I want to commend what we already achieve, but not shirk the challenge of how far we have still to travel. We need to be valued by ministers and recognised by external bodies as a superb source of expert, objective policy advice, trusted by all to be honest, impartial and to act with integrity.
Mr O'Donnell set out his vision at - 21st Century Public Services - Putting People First - a conference attended by nurses, doctors, head teachers, the voluntary sector and civil servants at the QEII Conference Centre in Westminster.
He said that civil servants' thinking had to be relentlessly focussed on citizens and open to new ideas from outside. The civil service had no monopoly on policy advice or service delivery and did not seek one.
'Through vigorous management and improving skills, the civil service should strive for excellence in everything it does and work with and through partners to deliver for citizens.
'It is this culture which will maintain and strengthen public trust in the civil service for years to come. Because without the trust of the public, the civil service will not survive, and will not deserve to,' he said.
The Cabinet secretary acknowledged that the civil service was not living up expectations in all areas and echoed Sir David Normington's regret about recent problems at the Home Office.
'Some aspects of current performance must and will improve, and soon.
We are fully committed to tackling these issues, and urgently.'
Mr O'Donnell's full speech is available here.