Jersey's medical officer of health Dr Susan Turbull has announced she will be retiring after 40 years of public service.
The Government of Jersey said recruitment would start "shortly" for the role, with Dr Ivan Muscat continuing to lead the island's medical response to the pandemic.
Dr Turnbull has been the island's medical officer of health for nine years, after moving to Jersey in 2006.
She said now was "the right time" to return to the UK to spend time with her family.
"I've had a wonderful, varied career and have been privileged to serve the island for the last 14 years," she said.
"I'm confident that the island remains in safe hands with the expert advice of Dr Ivan Muscat and the medical leadership of Mr Patrick Armstrong to help steer our health services."
Dr Turnbull only recently returned to her role in April following a period of sick leave.
She was responsible for the island's response to the 2009 Swine Flu pandemic, as well as delivering an innovative immunisation programme and improved initiatives for bowel screening.
Minister for Health and Social Services Deputy Richard Renouf thanked Dr Turnbull for her "dedicated service" to the island.