Dr. Jessica Myrtle "Jessie" Spano is the current guidance councillor at Bayside High, where she formerly attended during her teen years. Previously, during her attendance at Bayside, she was best friends with Zack, Screech, Lisa, and Kelly; she was, and arguably still is, the smartest person in the group.
Jessie's position at Bayside, the school in which her son Jamie attends, often puts Jessie in a complex position wherein she must chose between doing the right thing and helping her son navigate teenage life.
She and Zack live next door to each other, and Zack regularly visits Jessie by climbing through her window. She lives with her mother, who remarried in the third season, providing Jessie with a stepbrother, Eric from New York City, seen in only two episodes. Jessie's father is the owner and manager of the Marriott Desert Sands resort. He is also remarried, to a much younger woman with whom Jessie did not initially get along and was against marrying. She eventually accepted Leslie.
Jessie cracks under the pressure of getting a bad grade in geometry, worried that it will have a massive impact on her chance at making it to Stanford. She starts taking caffeine pills in order to stay awake to study for midterms, to get in more studying. Ignoring Slater's warning, she continues to take them. One morning, Zack goes round to Jessie's house to wake her up, when she has a breakdown. Zack didn't believe Slater when he warned him about Jessie.
It is discovered Jessie's parents are divorced and both are remarried during Season 3. Her mother's remarriage introduces a conniving stepbrother from New York named Eric (played by Joshua Hoffman) in a 2-part episode, although neither her mother nor stepfather are seen, however. In another 2-part episode, her father marries a much younger aerobics instructor named Leslie, whom Jessie initially disfavours.
Jessie fully expected to be crowned valedictorian, but finished a fraction of a point behind Screech. Angered over having to accept the salutation position, she swore to make him miserable in order to make him give back the position to her. However, Lisa comes to Screech's defence and wisely calls Jessie out for being selfish. She pointed out being valedictorian means a lot to him and she saw first hand how caring he was in helping Zack come up with a ballet performance to help him get the missing credits. Lisa also mentions that Screech only gave up the position of valedictorian because he knew how much it meant to her as well and didn't want to hurt her feelings by fighting over it. Only then, Jessie regretted how much she hurt his feelings and realizes how much being valedictorian means to him. She does the right thing and gives it back to Screech.
Upon graduation, Jessie attends Columbia University, although she had been hoping to get into Stansbury (fictional) in one episode, and had applied to several Ivy League schools.
Jessie attends Columbia University although she long expressed a desire to attend Stanford University and likewise displayed interest in the fictional Stansbury College, as well as various other elite universities.
Position at Bayside
Jessie is comfortable in her position as Guidance Councillor at Bayside High, but finds that this comes with numerous difficulties. Jessie finds it difficult to see her son, Jamie, replaced as quarterback of the Bayside Tigers, and confronts Slater about the issue. Slater tells Jessie that he only allowed Jamie on the team due to the friendship between the two, much to Jessie's surprise. Jessie, however, has trouble explaining to Jamie that he is bad at football, and instead sugar coats the situation, remarking that he should embrace Aisha's new position on the team.
Later, Jessie advocates for the staff members at Bayside supporting the student led walkout in favour of the Douglas students remaining at Bayside. She convinces A.C. Slater, Principal Toddman and the remainder of the faculty staff at Bayside to join her when the students walk out.
Jessie is portrayed as a liberal, though she did have some controversial opinions (such as supporting Saddam Hussein's gassing of the Kurds). She is a second wave feminist. She is often the first to speak up when she feels something is unjust. Although seen as intelligent, Jessie has a somewhat neurotic streak.