Like other colleges in the University during the late 16th and early 17th centuries, Jesus College recruited from a wide age-range, with groups of brothers, cousins and young neighbours coming up to Oxford to be educated together, often by their private tutors. The lowest age-range of students was 12-15, with the majority aged 16-20, and some others, a few of whom were already in Holy Orders, in their early, middle or late twenties. These discrepancies in age evened out in the course of the 17th century; and, while some 15-year-olds were still entering the College after 1700, the oldest undergraduate entrants by that time were rarely over 22. Undergraduates were economically and socially stratified, the richest (and hence most privileged) being entered as noblemen commoners or fellow-commoners, the next two classes down as commoners or battelers, and the poorest as servitors. Admission fees were stepped accordingly, although all graduates paid the same College fee to receive a degree. Scholarships might be awarded to any class of undergraduate, depending on academic promise.

By the mid-19th century a few poorer students still paid the 5s servitors' admission fee, but all other distinctions had been abolished. The institution for which rules were laid down in the 1622 statutes resembled a tightly-organized seminary or boarding school, with compulsory philosophy lectures for graduates and scholars, and strict rules about recreation, attendance at Chapel, behaviour in Hall, and keeping within bounds. The Principal, Fellows and resident male servants (butler, cook and porter) were all enjoined to be celibate, and women were forbidden to enter the College precincts, even as bedmakers or laundresses. This, however, was clearly unenforceable, since one 'Goodwife Williams' held the salaried job of porter in the late 1650s. Despite the emphasis on hard study, only a minority of fellows taught, taking turns to hold lectureships in philosophy, logic, catechetical studies and rhetoric, and the responsibility for the junior or senior class. As in other colleges, most graduate scholars and fellows were eventually ordained clergymen, and left to occupy country livings and enjoy the freedom, once outside College, to marry.