Grandpa

Grandpa O'Reilly
Profile
Gender	Male
Species	Human
Family	Dextamina (sister) Dexter (grandson) Dee Dee (granddaughter) Dad (son-in-law) Mom (daughter) Fergle O'Reilly (son) Unnamed daughter
Interests	Science
First Appearance	The Grand-Daddy of All Inventions
Voiced By	Christine Cavanaugh

Grandpa O'Reilly is Dexter and Dee Dee's maternal grandfather, Dextamina's younger brother, and Mom and Fergle's father. He was voiced by Christine Cavanaugh.

Biography

Just like his grandson Dexter, he also has a laboratory, as shown in The Grand Daddy of All Inventions. However unlike Dexter's massive and high tech lab, his was a small space in his garage. Grandpa is also implied to be smarter than Dexter since, with a relatively simple set up he was able to create a self sustaining power source, which Dexter failed to do with his complex machinery.

Episode Appearances

• Old Man Dexter (Mentioned)
• The Grand Daddy of All Inventions (Official)

Trivia

• He is Mom's father since Mom refers him as "Dad".
• His design is identical to Dexter's future self, Old Man Dexter, indicating that Dexter inherits both his looks and genius from his grandfather.
• His only official appearance was in the episode The Grand Daddy of All Inventions however, he was mentioned in the episode Old Man Dexter.
• It is unknown what type of relationship he has with his son, sister, and other daughter.

Gallery

v · e · d Dexter's Laboratory Characters
Dexter • Dee Dee • Mom • Dad • Monkey • Major Glory • Quadraplex T-3000 Computer • Dog • Mandark • Oceanbird • Windbear • Douglas E. Mordecai III • Koosalagoopagoop • Pony Puff Princess • Action Hank • Lee Lee • Mee Mee • Phillips Luzinsky • Quackor • Puppet Pals • Number 12 • Action Dexter • Old Man Dexter • Executive Mandark • Overlord Mandark • Braindark • Old Gal Dee Dee
Villains
Mandark • Executive Mandark • Overlord Mandark • Braindark • Amy • Badaxtra • Boy Band Virus • Buzzard • Cap'n Ahab • Wet Willie • Captain of Chubby Cheese's • Chubby Helpers • Cindy • Claw • Crazy Robot • Darbie High Priestess • Darbie Collectors • Detention Warden • Dodgeball Bullies • Quackor • Dynomutt X-90 • Earl • Energy Thief • Fishing Rivals • Fishy • Gary • Becky & Gwen • Gooey Aliens • Gork • Gym Teacher • Human Dissecting Aliens • Hookocho • Ice Cream Man • Inter-Dimensional Monster • JoJo • Lalavava • Major Glory Gang • Master Computer • Mat Parallax • Mom's Rival • Ms. L • Paper Ninjas • Perfect Pony • Prison Warden • Red-Eye • The Robber • Rude Dee Dee • Rude Dexter • Shoe Gnomes • The Yard • Ultrabot 2000 • Ultrabot 4000 Observation Units • Yani
Minor Characters
Arnie • Barney & Betty • Beau • Big Daddy Fat • Big-Eyed Boy • Big-Eyed Girl • Billy Bloomberg • Blue Falcon • Candi • Cat • Charlie • Chris • Chubby Cheese • Computress • Dick McMann • Dexter's Friends • Dextamina • Dextor • Dextor's Parents • Doo Dee • Doreen • Dynomutt • Eccentric Man • Fergle O'Reilly • Grandpa • Herman • Jeff • Jimmy Smith • Jurassic Pooch • Katka • Lee Lee's Mom • Lisa (Babysitter Blues) • Lisa (Little Girl) • Lucky & Pierre • Mailman Mel • Mar-10, Fred and Tiny • Mary Weather • Mee Mee's Mom • Midge • Mike • Miss Babcock • Miss Pimmerwikle • Miss Wimple • Mr. Bunnydoodle • Mr. Chau • Mr. Fuzzums • NASA • Neighbor Lady • Ness Monster • Old Man McCowsky • Otto • Philian Poppyseed • Pirate Kid • Professor Hawk • Prof. Hawk's Fans • Professor Williams • Replacement Sisters • Ricola Man • Santa Claus • Smart Dad • Soyen Chen • Surfer Boy • Talking Dog • Talking Dog's Owner • Tattoo • The Ghost of Dexter's First Love • Tiki God • Timmy • Toshi • Trevor Winkle • Vicky • Yani's wife