This list is likely incomplete and/or incorrect. I alphabetized it for ease of cross-checking, though, because I am pretty confident in my knowledge of the 24 letters of the alphabet.
  1. β€’
    Morwenna Banks (🏦🏦🏦)
  2. β€’
    Jim Breuer (homophones count? 🍺)
  3. β€’
    Chevy Chase (πŸš—πŸš“)
  4. β€’
    Billy Crystal (🍷)
  5. β€’
    Jane Curtin
  6. β€’
    Robin Duke
  7. β€’
    Will Forte
  8. β€’
    Christopher Guest
  9. β€’
    Bill Hader (kind of...Haders gonna Hade.)
  10. β€’
    Halls; Anthony Michael, Brad and Rich
  11. β€’
    Jan Hooks (I cannot believe there is not a hook emoji. Another injustice for Jan.)
  12. β€’
    Tim Meadows (🌳🌳🌾🌾🌾🌾🌾🌳🌳)
  13. β€’
    Dennis Miller
  14. β€’
    Jerry Minor (πŸ‘ΆπŸ½)
  15. β€’
    Jay Pharoah
  16. β€’
    Chris Rock (πŸ’)
  17. β€’
    Charles Rocket (πŸš€)
  18. β€’
    Jenny Slate (🎬)
  19. β€’
    David Spade (♠️)
  20. β€’
    Nancy Walls
  21. β€’
    Noel Wells
  22. β€’
    Kristen Wiig (Honorable noun mention - that there is not a wig emoji seems unfathomable )
  23. β€’
    Fred Wolf (πŸ• - best I could do)
  24. β€’
    There are also several cast members whose names are verbs or adjectives or other parts of speech, including A. Whitney Brown (πŸ’©), Downeys; Jim and Robert Jr. (🐣), Tina Fey, Mary Gross, Rob Riggle (🐍), Martin Short, Cecily Strong (πŸ’ͺ).