- St. Mark's School - smlions
Maintained by the Communications Office
http://instagram.com/smlions
- St. Mark's Student Life - smsstudentlife
Maintained by the Dean of Students office
https://www.instagram.com/smsstudentlife/
- St. Mark's Alumni - smalumni
Maintained by the Advancement Office
http://instagram.com/smalumni
- St Mark's Photography Club
Maintained but the Photography Club
https://www.instagram.com/stmarksphotos/
Athletics
- Athletics: St. Mark's Athletics - smathletics
Maintained by the St. Mark's Athletic Department
https://www.instagram.com/smathletics
- Girls Varsity Soccer
Maintained by Girls Varsity Soccer team
https://www.instagram.com/smgirlsvarsitysoccer/ - Boys Varsity Soccer
Maintained by Boys Varsity Soccer team
https://www.instagram.com/smboyssoccer/ - Girls Crew - smrowing
Maintained by the coaches of the Girls Varsity Crew team
https://instagram.com/smrowing/
- Boys Crew - smmenscrew
Maintained by the coaches of the Boys/Mens Varsity Crew team
https://instagram.com/smmenscrew/
- Boys Varsity Baseball
Maintained by the Boys Varsity Baseball team
https://www.instagram.com/stmarksbaseball/ - Girls Cross Country
Maintained by Girls Cross Country
https://www.instagram.com/smgirlscrosscountry/