Dad (voiced by Jeff Bennett) is Dexter's and Dee Dee's blond-haired father is the stereotypical husband and head of the household, falling directly above his wife in authority.
Loves bowling, golf, fishing, and has an unnatural affinity for his wife's muffins, of which she can expertly create (according to him, the muffins are the reason he married Mom, though this may have been a spur-of-the-moment remark, since he desperately wanted the muffins at the time). Dee Dee's traits inherited from Dad include his cluelessness, naivite, high adility in sports, and blonde hair, though Dexter has inherited his need for glasses and obesession over petty things from him as well. In order to impress Dexter's classmates during "Bring Your Dad to School" day, he pretended that his career was that of an Evel Knievel- esque motorcycle stuntman, mentioning in passing that they wouldn't be too impressed if they found out he was a "boring old scientist". Like his wife, his real name has not been revealed and he is referred to as "dear", "honey", etc. As a baby, he was always a spoiled and rotten child, causing mischief and troublesome.
As shown in several episodes, such as "Better off Wet", Dexter's dad can be a bully, embarrassing and pulling childish pranks on his family for his own enjoyment. These often include pushing his family in the pool, farting on dexter, and very manipulative behavior. He shows little attention towards the words that exit Dexter's mouth, such as in "Dexter's Lab", where he completely disregards Dexter's statement of taking care of a dog being too much responsibility by assuming that Dexter wants the dog, all the while completely ignoring Dexter's open lab located directly behind him.
His workplace may also be in an office as when Dee Dee takes pictures of him dressed as mom and she says "Wait till the boys at the office see these" in "The Muffin King".
The only thing close to being named was in the episode "Bad Cable Manners" where everyone refers to him as "Mr. Dexter's Dad".
Once tried to get his son into sports, but by episode's end it didn't work. He was once seen smoking a pipe in one episode. While his intelligence is far below that of Dexter's he sometimes gives good advice such as advising Dexter to get his glasses fixed after they were regarded as "cool". Dexter's father normally tends to show favoritism to Dee Dee for her athletic prowess, but will occasionally side with Dexter when facing a challenge between the sexes (such as the snowball war between Dee Dee and Dexter, which he treats as a life-and-death matter in which Dexter must avenge his father being hit with a snowball thrown by Dexter's mother back in college). Dad is also depicted as unreasonably hostile towards everybody when they interfere with a sports-related activity such as watching the "biggest golf match of the year" or breaking his bowling trophy.
His would Sometimes visit Dexter and spend father son time together.