S.H.I.E.L.D
Sabretooth
Sandman
Sauron
Scalphunter
Scarlet Spider
Scarlet Witch
Scorpion
Scott Lang/Ant-Man
Scrambler
Scrier
Sebastian Shaw
Senator Kelly
Shadow Knight
Sharon Carter
Shatterstar
Shi’ar Empire
Shocker
Shriek
Shuri
Silverfox
Silver Sable
Silver Surfer
Skids
Skrulls
Skurge the Executioner
Sonny Burch
Speedball/Robbie Reyes
Spidercide
Spiderman
Spiderman 2099
Spitfire
Starfire (DC Comics)
Starfox
Starjammers
Star-Lord
Storm
Stryfe
Stunner
Sunfire
Sunspot
Superboy (DC Comics)
Superman (DC Comics)
Supernova
Super-Skrull
Supreme Intelligence
Surtur