Prince Alfred College is a private, independent, day and boarding school for boys, located on Dequetteville Terrace, Kent Town, near the centre of Adelaide, South Australia. One of the most expensive and oldest private schools in the state, it has educated Rhodes Scholars, premiers and politicians, leaders of industry and finance, senior public servants, explorers and sportsmen. The school has maintained a worldwide alumni network, run by the Old Collegians' Association (PAOCA), since 1878. Alumni of the school are known as Old Reds.

There is presently an enrolment of some 1,420 students from Reception to Year 12 (ages 5 to 18), Prince Alfred College launched its own Early Learning Centre in 1999 with a current enrolment of 260 co-educational students.

As a school with Methodist roots, it has maintained a strong connection throughout its history to the dual ideals of "muscular Christianity and the Christian gentlemen", consciously seeking to shape the next generation of men through physical and intellectual discipline. The school has a strong sporting culture and undertakes numerous outdoor programs. There is a historic sporting rivalry between the school and nearby St Peter's College, which has religious and intra-class origins. The Intercollegiate Cricket Match, played each year between the First XI of the two schools, is considered the second oldest known ongoing cricket contest in the world, having begun in 1878.

The school has been the subject of three histories written by, respectively, J. F. Ward (1883–1954), Ronald Malcolm Gibbs (1938-2015) and Rob Linn.

First conceived in 1854, the Wesleyan Methodist Church (Great Britain) in South Australia voted to create a school 'for the education of our sons' in 1867, at what is now called Old Methodist Meeting Hall on Pirie Street. The land in the suburb of Kent Town had been secured earlier at the sum of £2,750 with enough capital (£6,00) to build the first part of the main building. The creation of a Methodist school followed other successful attempts in New South Wales, Victoria and Tasmania. The new school was primarily intended to educate children of wealthy businessmen and farmers with a view to create future civic leaders steeped in 'large and liberal culture'. At the time, Methodism accounted for a quarter of the colony's population, partly because of the influx of Cornish miners.

T. G. Waterhouse and the Rev. John Watsford persuaded the Governor of South Australia, Sir Dominick Daly, to ask Prince Alfred, then Duke of Edinburgh, to lay the foundation stone at the new school during his tour of the Australian colonies. In September it was announced that Alfred would lay the stone and that the new school would be the 'Alfred College'. The stone was laid on 5 November 1867 at 2pm.

The only female student to attend the school was Lilian Staple Mead, daughter of Baptist minister Silas Mead, in 1883–1884, in order to matriculate and enter University at a time when few schools were available for girls to do so.

The school has attracted many royal visitors since its foundation, including Queen Elizabeth II and Prince Philip in 1954. In the 1970s, the Prince Alfred College Foundation was created under the direction of businessman, W. Geoffrey Gerard. Its first project was the Scotts Creek outdoor campus located at Mannum in country South Australia, before developments at the preparatory school, gymnasium and boarding house. The Foundation quickly became the financial arm of the school responsible for many major redevelopments.