David Goodman, outgoing executive director of the Chief Rabbi's office, has been appointed acting chief executive of JNF UK.
The charity has also recruited Dan Sacker, once chairman of the Union of Jewish Students, from top PR firm Weber Shandwick, as director of communications.
The hiring of Mr Goodman, a former executive director of Kisharon Day School, follows last month's departure of Elliot Conway, who served as chief executive for six months.
His experience includes 12 years with the Israeli Defence Forces, much of it spent in the Negev which is now a key area of the JNF's work.
Mr Goodman said: "The JNF is one of the world's great Zionist organisations and it is an honour to be a part of it. Having worked closely with the JNF during my time at the Office of the Chief Rabbi with the development of the Lord Sacks Forest, I know first-hand the amazing work it does in Israel."
Mr Sacker has previously worked with American vice-presidential candidate, Senator Joe Lieberman, in Washington.
Samuel Hayek, JNF UK chairman, said: "I am confident they will help us continue to carry out the immensely important work the JNF is doing across Israel, and in the Negev region."