Rev Patrick Moriarty, 51, has been headmaster of the Jewish Community Secondary School, in north London since 2012, working 70 hours a week, managing 1,300 pupils and 100 teachers.
He will be further managing his time with his new appointment as assistant curate at St Mary the Virgin, in Barnet, following his ordination as a deacon in July at St Albans Cathedral.
Rev Moriarty told The Times that his church responsibilities were mostly restricted to Sundays, but he has already experienced having to exchange his casual clothes into clerical dress on a school day.
After he "nipped out to do a funeral", returning and changing clothes made him feel "a bit like Superman".
Asked how pupils have responded to his new Christian role, he said: "They just say 'Are those your vicar clothes sir?' Nobody really bats an eyelid, but I do try not to wander around school like that. It would be confusing in any workplace, but it certainly is as head of a Jewish school."
Rev Moriarty was brought up by a mother on the church's General Synod and a father who was a church commissioner.
Describing his personal faith, he told The Times: "Becoming ordained was something that has been in my consciousness for a long time. You could say it's been a 35-year gestation process.
"That nagging sense kept coming back to me, saying, 'You need to take this deeper'."
Rev Moriarty informed parents of the state school before he was ordained.
In a newsletter to them in May, he wrote: "From July I can officially use the title 'Rev' (like a Rav [the Hebrew word for rabbi], but with different outfits . . .) and wear the clerical collar; I have no plans, however, to do either at JCoSS, and the day job will continue just as before."
Rev Moriarty's colleagues have supported and encouraged him for what he described as a "rather unusual path".
He received cufflinks and socks that said "Trust me, I'm a vicar", and well-wishes from many parents and governors, relieved that his new role didn't mean he planned to resign.
Jeremy Kosky, chairman of the school's governors, told The Times: "The governing body is proud to have a non-Jew as its head teacher and prouder still that he has been able to find time to take his own religious beliefs to the next level."
These words of encouragement were echoed by Rev Moriarty's new colleagues at St Mary the Virgin.
Rev James Mustard, the rector of East Barnet, said: "Patrick's work within the Jewish community, and in wider inter-faith circles, is incredibly enriching for us, as I hope our prayers and support are enriching for him."
