Dr. Bart Fortuna is a friendly scientist who first appears in a "Nice One, Jessie". He is the father of the Jessie Fortuna. He was voiced by Jason Segel.
- He is intelligent, smart and friendly.
- He is very slender, light skin, brown messy hair, mustache and wears goggles with green lens, white lab coat, green necktie, black shirt, pants and shoes.
- His last name is similar to the Bib Fortuna from Star Wars.