Dexter's Laboratory Wiki
Ferguson O'Reilly
Aliases Ferguson
Gender Male
Species Human (possibly a leprechaun)
Family Grandpa (father)
Dextamina (aunt)
Mom (sister)
Dexter (nephew)
Dee Dee (niece)
Dad (brother-in-law)
Unnamed sister
Occupation Magician
Interests Magic
First Appearance That Magic Moment
Voiced By Mark Hamill

Ferguson "Fergle" O'Reilly is the brother of Mom, and Dexter and Dee Dee's magic maternal uncle. Him, Mom, Dexter, Dee Dee, and Grandpa may be Irish.


Fergle O'Reilly is a short man, just a little taller than Dexter, and has curly red hair (a little darker than Mom’s) and black eyes. He wears a formal white shirt and tie with a green jacket, pants, shoes and hat. His overall appearance makes him resemble a leprechaun (which he may actually be considering his unique magical abilities).


  • He is based on the comedian Ed Wynn.
  • He has not been seeing interacting with his father, aunt, and other sister.