Reunion organisers said Mr English had reflected on his "passion and love for" the college.
The three-day celebrations attracted about 270 former students of the college, and concluded yesterday with the 10am blessing of Fitchett House, a new student accommodation facility in Dundas St, a church service at All Saints’ Anglican Church and lunch at the college.
College warden Ashley Day said the reunion had been "absolutely outstanding".
There had been many highlights during the reunion, which attracted a high-powered line-up of former college residents, including Mr English, Health Minister David Clark and former All Black David Kirk.
Among highlights were a golf event and cocktail function on Friday, a tour of the university campus on Saturday, an afternoon cricket match between current and former college students, and a dinner at Toitu Otago Settlers Museum on Saturday evening.
Mr Day said Mr English spoke movingly about the important role the college played in his life as a young person, saying it had helped "form his life" and develop further from his initial origins in rural Dipton.
University vice-chancellor Prof Harlene Hayne also spoke at the dinner.
The master of ceremonies was High Court judge Justice Simon Moore, also a former Selwyn resident (1972-73).
College organisers said that Fitchett House, with its 15 bedrooms, would become part of Selwyn College from next year, and could prove suitable for postgraduate student accommodation, linked to the college.
The name honours the former dean, the Very Rev Alfred Robertson Fitchett (1836-1929), and recognises the Fitchett family’s long association with the college.