Nicholas "Nick" Katsopolis I is Jesse and Pam's father. He is an avid fan of Elvis Presley, just like Jesse. Also, like his son, he is very much interested in his hair and ladies (according to him in the season two episode "Our Very First Christmas Show", "there are two things Katsopolis men are known for: kissing and great hair"). He owns his own business, in which he is a bug exterminator. He met his wife, Irene, the day that Elvis was drafted. Nick was a strict but loving father. In the episode, "D.J. Tanner's Day Off" it is mentioned that he would punish Jesse severely. This combination is also seen in the episode "It's Not My Job", when Jesse quits the extermination business Nick responds with: "If you're out of the business, you're out of the family." Later on, he explains this by saying that he did not build up the business to sell it to a stranger. Also, his love for his family is shown by the fact that Irene bringing in Michelle curbed his anger. When Michelle was getting ready to do a TV commercial for marshmallows (the season two episode "El Problema Grande de D.J."), he remarked that Michelle looked like a little blonde version of the redhead he likes on the TV show Gilligan's Island, which was revealed to be Tina Louise by Irene.
In "Fogged In", when he and Irene stay over at the Tanner house after a huge fog covered San Francisco, he got into the dispute over whether or not Danny should let D.J. have a drum set; thus, Danny thinks this is where Jesse gets his "buy-off" behavior from. At the end of the episode, during his chat with D.J., Jesse himself mentions that Nick used to buy him off with a Batman comic book to settle a dispute or problem.
In the Fuller House episode "Wedding or Not Here We Come", he babysits Tommy, while D.J., Stephanie, Kimmy, Fernando Guerrero, Ramona Gibbler, Jackson and Max all went to Japan to Steve's and C.J.'s wedding.