Since 1985, Jonathan Ullmer MBE has concentrated his educational interests and skills on increasing the educational experiences of pupils both domestically and globally. As the CATS Colleges' founding Director of Education and Principal, he transformed two schools from "unsatisfactory" to "excellent," with leadership recognized as "exceptional" by UK inspectors. The purpose of the CATS colleges is to help international students prepare for university achievement and to improve their English abilities as they pursue a career in the arts.

Jonathan Ullmer earned a Distinction in Teaching Practice after studying English at Durham and Oxford Universities. He earned an MA in North American Literature from the University of Victoria in Canada. He also holds a diploma in the Therapeutic and Educational Application of the Arts from the Institute for Arts in Education and Therapy, as well as the Royal Academy of Music's LRAM accreditation as a Teacher.

Mr. Ullmer began his teaching career in 1985 at Swanley School in Kent, where he taught English and Drama. He started as the Arts Curriculum Director at Cecil Jones High School 11-18 Foundation School in Southend in 1989 before going on to Sawyers Hall College of Science and Technology in Essex as Assistant Principal in 2002. In 2008, he became Vice Principal of CATS College Cambridge before becoming Principal of CATS Canterbury, the oldest CATS College, in 2010.

Jonathan accepted an offer from Haileybury to run their school in Kazakhstan's capital, Nur-Sultan, in 2017. Jonathan's expertise in school improvement brought him to the city school, where he collaborated with the teachers to guide Haileybury through a highly successful inspection, in which the school was rated as having outstanding international practice in 17 of 19 areas.