SCIENCE, from the Latin word scientia ("knowledge"), is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the natural world. Through systematic observation, measurement, and experiment, scientists understand as well as formulate, test, and modify hypotheses.

The ‘Iolani Science program strives to impart to students a love of science, an understanding of key concepts, and to help students develop the tools and skills to become scientifically literate citizens of the 21st century. Throughout the ‘Iolani Science program, students observe, hypothesize, perform experiments, write up their observations, and draw conclusions.

The Lower School years (grades K - 6) allow students to explore the natural world.  Science specialist teachers focus exclusively on science in two fully equipped science laboratories. A designated outdoor area provides hands-on experience in composting, gardening, and other outdoor science. Students take field trips, participate in community service, and engage in environmental awareness projects. Parents, community professionals, and older ‘Iolani students visit classes, further enriching the program. Special programs occur at all grade levels including a third grade "Space Night" where students and their families camp overnight, use telescopes to observe the night sky, and participate in expert-led science activities.

During the Upper School years (grades 7 - 12) students deepen their scientific knowledge and further develop as young scientists. All courses involve substantial, hands on laboratory work so students both learn and practice concepts.  Science teachers, each an expert in their respective field allows specialized, focused instruction. Fully equipped laboratories and additional lecture rooms allow ample space for students to investigate and learn. The average Science course size is small enough to allow individualized attention for students both inside and outside of the laboratory.  In grades 7 and 8, students explore Earth Science and Physical Science. Once students reach the high school years (grades 9 - 12), there is a three-year sequence of biology, chemistry, and physics. Students have the option of taking a fourth year of high school science, earning Advanced Placement college credit in biology, chemistry and/or physics.

A wide variety of extracurricular activities allow students to further explore science outside of the formal classroom setting from third grade through graduation. In the area of robotics, ‘Iolani fields several First Lego League Teams, multiple VEX robotics teams, and a FRC Robotics Team. ‘Iolani has three Science Olympiad teams for middle and high school students, a Science Bowl team, and supports older students in directed summer research.