Natural England chief executive Helen Philips will be leaving the organisation on 1 March to take up a post as executive director of Yorkshire Water.
Dr Philips took the post five years ago when NE was created and has headed the organisation through a period of turbulent change and resource challenges.
NE chair Poul Christensen described her as a transformational leader who created the new organisation, improved efficiency, built a customer service culture and secured a series of important environmental outcomes.
"Helen will leave behind an organisation that has adapted to the new government's priorities for its arm's length bodies, and whose record of delivery enables Natural England to face the future with confidence," he said.
"Under her leadership, Natural England has made its evidence accessible, notably through the publication of the State of the Natural Environment Report, increased to 70% the amount of farmland in environmental stewardship, prioritised support for the government's natural environment white paper and the new England Biodiversity Strategy and achieved favourable and recovering condition for over 95% of England's most important wildlife sites."
Environment minister Richard Benyon said that NE had made a real difference to the environment under Dr Philips' leadership.
Dr Philips said it had been a privilege working with dedicated and talented people.
"I am proud of what we have achieved together and will move to Yorkshire Water confident in the knowledge that Natural England is well positioned for the future," she said.
