Classes continued steadily until 1940 when the German occupation severely disrupted education. Half of the population, including most of the teachers, were evacuated to England. However, even under these difficult circumstances, evening classes continued at the Guilles Alles Library where subjects on offer included German, French Bookkeeping and Agriculture.

In 1947, Mr Fulford retired and the following year the Education Council appointed a Mr Roberts in the full-time position of 'Further Education and Youth Officer' with a budget of £648.00. In 1950, by which time there were almost 1000 enrolments in 70 classes, Mr Roberts was replaced by Mr McVay, who continued in his post until 1967.

During the sixties, local employers began to take a greater interest in vocational training and put pressure on the Education Council to provide better facilities for such training.

In 1968 Mr Mike Hutchings was appointed as 'Further Education Officer' and the following year, after consulting with local employers, he placed proposals before the Council for a Technical Training Centre offering day courses in a range of classes, including Carpentry, Electrical, Motor Engineering, Plumbing, Horticulture and Hairdressing.

The centre opened in 1969, with 5 full time lecturers teaching in poorly equipped, converted rooms within the Education Council building. Initially there were 213 apprentices in 11 day release classes and it quickly became clear that purpose built premises were required.

In 1970 the States approved the expenditure for such a building and in 1971 the Technical Training Centre was renamed the Guernsey College of Further Education. The first Principal, Mr. Charles Hunt, was appointed, and the full-time staff numbers were increased to ten. The purpose built premises at the Route des Coutanchez were completed and occupied by the College during the academic year, 1975/6.

In 1986, the College had outgrown its main site and moved some classes into the old Boys' Grammar School at Brock Road. This was intended as a temporary measure for no more than five years! In 1992, the College was given the use of Grange House which is now used by the Art & Design programme area.

In 1995, the College established a Management Centre to deliver bespoke courses to local companies. In 1998 the Management Centre merged with the Finance Studies programme area to create the Guernsey Business School, offering a range of courses to local industry.

The College's newest building - the Princess Royal Centre for Performing Arts was officially opened by Princess Anne on 11th June 2007, the centre offers vocational perfoming arts courses plus a range of part-time and short courses. The centre also provides a new rehersal base for the Guernsey Schools Music Service.

In September 2008 Guernsey College expands into the former St Samsons School Site, renamed the 'Delancey Campus' and looses two locations, Longfield and Grange House with Tutors and Students moving to Delancey.

Since the early seventies when the main site was opened, the College has continually responded to the community's needs and now employs the equivalent of over 75 full-time lecturers as well as a considerable number of part-time staff. In the academic year 2007/8, over 3000 students enrolled on vocational courses as well as 3000 students on the Adult Education Programme.