Rabbi Naftali Brawer has announced his resignation from Borehamwood and Elstree Synagogue to take on a new public role.
The American-born minister, who will leave in August after four years with the congregation, is to lead a foundation dedicated to promoting spirituality at work.
He told members in a letter that he "certainly did not plan to do this sort of thing when I became a rabbi, and yet after serving in that capacity for close to 20 years, I have been presented with an extraordinary opportunity to positively influence wider society".
Borehamwood chairman Anthony Arnold said he would have liked Rabbi Brawer and his wife Dina - a Jewish educator in her own right - to continue leading the community. But an interim minister would be appointed until a permanent successor as senior rabbi could be found.
