Andrew Sells' to-do list includes playing a central role in delivering Defra’s 25 Year Plan for the Environment, and ensuring Natural England follows through on its Conservation 21 strategy.
He said the role was "exceptionally important in fulfilling our responsibility to protect and enhance the natural environment".
Leadsom said: "I am very grateful for Andrew’s leadership, hard work and achievements over his first term and very much look forward to continuing to work with him."
She said she valued the advice of Natural England highly and said it did vital work to safeguard our environment.
Sells’ new appointment will run from 20 January until 19 January 2020, with an annual salary of £61,698 for 113 days’ work a year.
He was chairman at Wyevale from 2009 to 2012 and chairman of specialist brown field developer Linden Homes from its start-up in 1991 until its sale in 2007. A chartered accountant by profession, he has also been a trustee and held the post of treasurer at both the RHS and Policy Exchange.