Two sixth-formers at Yavneh College have said that Jewish education has not prepared them for mixing with people outside their faith group.
Shir Dor, deputy head girl at the school, and Simmy Wahnon, both 17, said they were concerned that their peers were not prepared for the "real world".
Many pupils at Jewish schools would arrive at university never having met a non-Jew before, they said.
The two students are taking part in an interfaith project called Near Neighbours, run by the Church Urban Fund, aimed at bringing together people from different communities to work on social action projects.
Speaking last week at a reception at Lambeth Palace, Ms Dor told the 200 guests, including Justin Welby, the Archbishop of Canterbury, and Chief Rabbi Ephraim Mirvis: "Taking part in this project was the first time I've spent any real time with people who are not Jewish."
I worry that my friends will end up at university never having met a non-Jew
This week, the teenager from Borehamwood, told the JC: "Because I've always been to Jewish school and all my friends are Jewish, it was really interesting to meet new people and learn about other faiths for the first time.
"Of course we've learnt about them in school, but I had never really integrated with Christians or Muslims before and it has taught me that it is OK to be different."
She said not knowing any non-Jews was certainly something she worried about before taking part in the project.
She added: "I don't worry about it now because the project taught me how to talk to people and tell them about my Jewishness and ask about their own background.
"But I do worry for my friends who haven't taken part in a project like this because a lot of them will end up at university having never met someone who is not Jewish."
Mr Wahnon, who hopes to study medicine at university, said: "I think the faith-school system has its advantages but interfaith work has dropped off the radar.
"Living in the [Jewish] bubble is a social ill we are all aware of and it doesn't aid the fight against antisemitism to keep ourselves separate.
"I think we have grown too comfortable with not mixing."
He said that because of Near Neighbours he was better prepared for life outside of "Jewish education and youth movements".
Mr Wahnon added: "I think my school has been great in giving me this opportunity and, going forward, I think it is something all Jewish schools should be thinking about doing more of."
Paul Hackwood, executive director of Near Neighbours, said: "Through our work, young people get together for four-day courses and look at a number of things with their peers from other groups over the time.
"They try and understand how different faith communities work, then hopefully take the message back to their own communities."
Laura Marks, who is co-chair of Nisa Nashim, the Jewish-Muslim women's network, attended the Lambeth Palace event. She said she was impressed with the "honest" speeches delivered by the Yavneh students.
"My concern is that Jewish people should be known to the outside world and for Jewish people to know the outside world. Moving forwards, we don't want to be in the same situation in 20 years, so we have to find ways for people to meet each other."
Rabbi Jonathan Romain, a prominent critic of faith schools, said the concerns expressed by the two students were a "wake-up call".
"Of course we have to be strong in our Jewish education and Jewish identity but not at the cost of ghettoising ourselves and cutting ourselves off from other communities," he said.
"It raises major questions about how it is for children living in exclusively Jewish environments."
A Board of Deputies spokesperson said formal linking programmes with other faith- and non-faith schools should "be better supported and funded" to ensure that children get to know those who have different backgrounds to their own.
