Some of Sydney's most prestigious private schools have become Anglo-Australian ghettos as the education of high school students across the city is increasingly segregated along ethnic lines.

Students with a language background other than English made up 52 per cent of all enrolments in Sydney's public high schools in 2011 while the share in independent schools was just 22 per cent, research by the University of Technology Sydney's Dr Christina Ho has found. The proportion in Catholic schools was 37 per cent. "Schools are becoming more segregated in terms of both class and ethnicity," Dr Ho said. "More and more students are going to schools that do not represent the range of people in their neighbourhood, but rather a select group."

St Ignatius Riverview has five per cent of students from language backgrounds other than English.

The segregation trend was very pronounced on Sydney's lower North Shore, home to some of Australia's highest fee private schools. Ho identified 11 private high schools in the area where the proportion of students from language backgrounds other than English was at or below 20 per cent. Queenwood School for Girls in Mosman had the lowest share (2 per cent) followed by St Ignatius College Riverview in Lane Cove (5 per cent) and Monte Sant' Angelo Mercy College in North Sydney (6 per cent).

However, in two selective public high schools in the area - North Sydney Boys and North Sydney Girls - the proportion of students from a language background other than English was above 90 per cent. At the nearby comprehensive public schools Chatswood High and Willoughby Girls High the proportion was 76 per cent and 57 per cent respectively. "You can walk between some of these schools in a few minutes and yet one is like a white bubble and the other is like a non-white bubble," Dr Ho told the Herald. "Its astounding that this can be happening in the same suburb like say, North Sydney."