"Turning 100 is a wonderful opportunity for St Matthew's to remember its past, reflect on the present and look to the future," said St Matthew's Centennial chairwoman Anna Perry.
"Apart from the exciting activities and events planned, it's a wonderful opportunity to catch up with old friends and teachers and relive some fond memories," Mrs Perry said.
Rathkeale College Jubilee chairwoman Lisa Sims said interest "so far has been fantastic" and hundreds of old girls and boys from throughout New Zealand and overseas were registering for the celebrations through the event website.
"Many are looking forward to enjoying the great hospitality Wairarapa is known for and we expect our visitors to fill up the town," she said.
"The schools are also keen to receive anecdotes, memories and archive material from former pupils, staff and friends. We're looking for stories that illustrate what school life was really like," Ms Sims said.
"We'd also like to hear from people with photos, books, old school uniforms or any other memorabilia from the early days." Both schools are working hard to track down former pupils and staff.
Email address for St Matthew's Collegiate School: centenary@stmatts.school.nz. For Rathkeale College: jubilee@rathkeale.school.nz. Registrations can be made at: www.thebigweekend.school.nz.