It is not generally known that Mrs Galloway (84) won a bronze medal in the Australasian freestyle relay team at the London Olympics in 1948.
"The relays were held on the last night of swimming and I still have the medal," Mrs Galloway said.
Mrs Corlett (80), the first New Zealand woman to win an Olympic gold medal, is recovering from the severe health problems that have plagued her for the past few years.
"I had an abscess on my brain, had two operations and was in hospital for three months," Mrs Corlett said.
"I couldn't walk or talk. I also had an operation for bowel cancer."
Mrs Corlett won the long jump at Helsinki in 1952 and is one of 11 Olympians from the school.
The only other gold medallist is Jenny Armstrong in yachting's 470 class when representing Australia at Sydney in 2000.
"I didn't know there were so many Olympians from the school," Mrs Galloway said.
There is another honours board for the other 35 New Zealand representatives, which includes Lois Muir (nee Osborne), netball, Shireen Crumpton (nee Rough), athletics, Anna Thomas, diving, Anna Frost, mountain running, and Kelly Brazier, rugby.