The hotline will allow whistleblowers to pass information about individual doctors or organisations to trained advisers who can pass it on to the GMC for investigation.
Callers can also be directed to other appropriate organisations, such as the Care Quality Commission.
The helpline will operate during normal business hours, but will include the facility to call doctors back at a time of their choice.
An online decision aid to help doctors report patient safety concerns has also been launched by the GMC.
The online tool can guide doctors through the process of raising concerns and sets out what they need to do if they have concerns about the conduct of colleagues, systems in place, staff shortages and other operational issues that impact on patient safety.
It also includes case studies to illustrate how doctors may handle incidents themselves and more challenging situations that require involvement from a regulator or other external body.
GMC chief executive Niall Dickson said: ‘In the past, many doctors have felt uneasy raising concerns about policies and procedures or about their colleagues.
‘We hope this new service will be useful in helping them navigate their way through the system. We also hope it will give doctors the confidence to act when they have concerns.'
Dean Royles, director of NHS Employers, said: ‘We believe it is important that employers, regulators and other professional bodies work together to constantly reinforce messages to reassure staff that they can speak openly, and we are delighted to be able to support this initiative from the GMC.’
The launch of both services follows the publication of new GMC guidance for doctors, Raising and acting on concerns about patient safety, which was sent to every doctor in the UK earlier this year.
GMC confidential helpline number: 0161 923 6399