• 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/