The International Baccalaureate was developed in 1968 in an effort to establish preparatory school standards that universities recognized as rigorous and effective in preparing students for higher level studies. IB has been in American schools since 1980 and at Norcross High School since 1997. An International Baccalaureate Organization survey suggests the program’s positive influence on American university acceptance rates: IB seniors in the US are accepted into premier universities more often than the general admission pool of applicants. Moreover, students who complete the Diploma Program graduate at a higher rate from universities than those who complete other high school courses of study.

Students opt in to the The IB Diploma Program when at the beginning of their junior year. Whether students choose to participate at the Full Diploma level or at the Course Candidate level, highly motivated and academically focused students will find a rigorous and diverse educational experience in IB at Norcross High School. The program is an interdisciplinary curriculum, but the Program emphasizes how students learn in addition to course content. The advanced course work promotes students' intellectual, personal and social development. 

While there are not substantive differences in the ways instructors deliver their courses to Course candidates and Diploma candidates, there is an important difference in course selection for the two programs. Course candidates select some IB courses and some traditional courses at NHS, while Diploma candidates must take a full schedule of IB courses. Exclusive to Diploma candidates, the centerpiece of the Diploma program is Theory of Knowledge (ToK), an interdisciplinary course intended to stimulate critical reflection upon how we form knowledge and how our experiences inside and outside the classroom shape what we know. ToK unifies academic subjects and encourages appreciation of other cultural perspectives.