Caltech traces its origins back to the Throop Polytechnic Institute of 1891. Caltech has been coeducational since 1970, but men still greatly outnumber women. Total enrollment is about 2,000 students, with undergraduates numbering about 900. Approximately a third of the students are state residents, and Asian Americans make up about a quarter of the student body. Four fifths of the students live in campus housing.

Caltech conducts degree programs from the bachelor's through the doctoral level. Both its students and its faculty are distinguished. Students have some of the highest standardized test scores in the United States, especially in math. Almost all were in the top 10 percent of their high school class, and many were National Merit Scholars. The faculty includes numerous Nobel prizewinners, and all of the full-time staff hold doctorate degrees. To encourage an atmosphere of trust in an intense environment, everyone at Caltech is expected to follow an honor system, which states that “no one shall take unfair advantage of any other member of the Caltech community.”

The academic calendar is divided into quarters. Caltech was the first scientific institution to require undergraduates to take at least 20 percent of their courses in humanities and cultural studies. An exchange program with area liberal arts colleges enables interested students to take these courses at other institutions. All students at Caltech study math, physics, and chemistry. Students major in disciplines within the fields of physical science, mathematics, geology, astronomy, engineering, and biological science. Caltech has a program that grants summer research fellowships to 200 undergraduates. The students work on independent projects under the guidance of a faculty sponsor, and many have their work published in scientific journals. About three fifths of students pursue advanced degrees within a year of graduating from Caltech. Caltech's own graduate programs focus on biological, physical, and social sciences; engineering; computer and information sciences; and mathematics.

Caltech offers students some 90 extracurricular activities, including musical, academic, professional, and religious groups. The student government organizes social events, such as weekly movies, and governs matters concerning the Institute's honor code. Almost three fourths of the students participate in one or more intramural sports, and Caltech's Battling Beavers participate in varsity competition in Division III of the National Collegiate Athletic Association. School colors are orange and white. Caltech has a reputation for exotic stunts. The annual Pumpkin Drop has students immersing a pumpkin in liquid nitrogen for several days and then dropping it from the library rooftop on Halloween, shattering it into millions of pieces. Another popular event is Ditch Day, when seniors use sophisticated and unusual methods to barricade their rooms and then leave campus while underclassmen figure out how to get inside to capture a reward. Perhaps Caltech's most memorable prank was during the 1984 Rose Bowl game (UCLA vs. Illinois), when some students created a radio-controlled device to take over the scoreboard. The board flashed pictures of their own school's mascot and altered the team names to read Caltech and Massachusetts Institute of Technology, with the score showing Caltech beating their academic rival.