St. John’s is a full member of the International School Sports Tournament (ISST) organization. There are 13 full-member schools in this league. Schools are located across Europe and tournament venues are rotated annually. The ISST is fundamentally a Varsity athletic organization which governs competitive athletic championships for its 13 member schools. The ISST currently sanctions eleven sports for 22 championships annually across two divisions.
For the fourth consecutive year, St. John's has ranked in first place among ISST schools (for schools with a High School enrolment up to 300 students), receiving the Eddie Hufford plate. The plate is awarded to "the ISST school that reflects the high standards of sporting excellence that has always been a fundamental principle of ISST participation."