Dereck Morris aka Peter Morris (Zack's Dad)
- a busy man that works much of the time. Zack in one episode resorts to using a cell phone to talk to him when he is in the same room. Zack hires actor James to impersonate his dad to cover up a bad grade in another episode.
Frank Kapowski (Kelly's Dad) - Kelly's dad, he loses his job in one episode and Kelly lies to her own father and tells him that she can live without the Prom to save money for the family.
Eric Spano - Jessie's stepbrother that blackmails Zack after seeing him on TV at a baseball game when he supposedly was out of school sick. Eric ultimately helps the gang repair Belding's car which was damaged. Appeared in a two part episode.
Casey Casem - appears near Bayside and the Max on a few occasions. He helps the gang during a dance competition and guides a retrospective of the rises and falls of Zack's band.
Rod Belding - Mr Belding's brother who comes to Bayside as a substitute teacher. The gang loves him and his easygoing nature. He promises the gang a white water rafting trip but then bails when a better opportunity comes for him. Mr Belding takes them on the trip instead.
Mr. Moody - owner of Mr Moody's store for men, and Kelly's boss at a job she has at the mall. He fires a girl because she was homeless. The gang comes to her rescue and Mr Moody sponsors a play the gang is putting on for Christmas. In a two part episode.