The University of St Andrews was established between 1410 and 1413. St Salvator's College is the oldest of the three endowed collegiate societies of the university. It was founded in 1450 and is known as the 'Old College'. It was founded as 'the College of the Holy Saviour"' by James Kennedy, Bishop of St Andrews and second Chancellor of the university, on 27 August 1450, in particular to sustain and develop the study of Theology within the University. He seems to have been inspired by the English foundations of New College, Oxford and King's College, Cambridge (1441). The collegiate church was integral to the community of Kennedy's college which aimed at the union of religion and learning, the ecclesiastical and the academic. The establishment of the college also represented Kennedy's considered attempts at reform of the University. This was to be achieved through the creation of a properly organised and adequately endowed college whose constitution would infuse regularity into the near-anarchy of the Faculty of Arts (based on the Pedagogy) and whose revenues would support a sufficient number of masters in dignity and security. By the time of the Reformation, St Salvator's College had become but one of three colleges within the University of St Andrews, yet it held the pre-eminent position in age, character and buildings.
Each of the post-Reformation proposals for university reform proceeded on the assumption that the three existing colleges would remain in being. The 'New Foundation and Erection of the three Colleges in the University of St Andrews' was ratified by King and Parliament in November 1579. The reorganisation this embodied was much needed after the confusion prevailing since the Reformation. The New College became a seminary of Protestant theology and St Salvator's and St Leonard's Colleges became 'philosophy colleges', offering parallel courses in Arts. Since St Salvator's College was the better endowed, it had additional tasks such as the Provost being 'professor in medicine'. The professorships of Greek and Rhetoric at St Salvator's were replaced by the professorships of Laws and Mathematics, transferred from St Mary's College where they had been instituted in 1574. These two were to be maintained, like the regents, from the common revenues of the college. However, within a few years, the posts lapsed. In common with the other Scottish colleges, the College of St Salvator came to consist of two clearly separated groups: the Provost and masters on the one hand and the bursars and ordinary students on the other. Over the next 40 years the Provost and masters gradually modified the scheme of the New Foundation to suit their less enlightened desires. Despite the arrangements set out for the four regents each to confine themselves to one section of the Arts curriculum, they stuck to their practice of 'regenting', teaching one set of students throughout the four years across all subjects. In 1621 the new Foundation was repealed and the old foundations of the colleges were re-established.
The General Assembly of the Church of Scotland of 1641 appointed a Commission to visit and reform the University. Between 1642-49 it attempted to return the college to the dual ideal of religion and learning for which it had been founded. It required parishes linked with the colleges to have their own ministers and the masters to be occupied in the work of the college. They also drove the master of St Salvator's College to appoint a regent of Humanity to teach Latin to the students to prepare them for their studies in philosophy and for the Arts course. The political upheavals leading to the Restoration meant that much of the detail of the recommendations of the Commission were not implemented. The staff of the college had stabilised at four regents or professors of philosophy and the new professor of Humanity. Between 1660 and 1690 the masters of St Salvator's College were prominent in the newly Royalist and Episcopalian university and thus, upon the abolition of episcopacy, the actions of the Commissioners of 1690 had a dramatic effect. On 24 September 1690 the corporation of St Salvator's ceased to exist by the disqualification of every one of its senior founded members. The abolition of the episcopacy also deprived St Andrews of its status as ecclesiastical capital of Scotland and the university of the influential patronage of the Archbishops. The whole trend of Scottish economic and social developments in the early 18th century was unfavourable to a residential university in a small town remote from the new centres of trade and industry. Student numbers declined from about 150 during the 17th century to about 80 in 1725 and about 20 in 1735. Revenues were increasingly unable to sustain the founded members and keep the buildings habitable. Ultimately, since the Colleges of St Salvator and St Leonard performed identical work, they were merged by Act of 1747 in the United College of St Salvator and St Leonard in the University of St Andrews. The masters of 1747 seem to have intended the traditions of their Colleges to be sustained and strengthened by their union. The buildings of St Salvator's were chosen as the permanent home of the United College and it was to remain a residential community until the last common tables in 1820.