"Glenn has clearly been an outstanding, world-class swimmer for more than a decade. During that time he has not only acted in a thoroughly professional and dedicated manner in the pool, but he has been a leader out of the pool," Cotterill said.
Snyders joins Dean Kent, Helen Norfolk and Lauren Boyle as the only New Zealand swimmers to contest three Olympics.
"Representing New Zealand in swimming has been an honour and a privilege," he said.
"To have been able to compete at the highest level in my sport for 12 consecutive years has been nothing but an adventure and life-learning experience, one that I will take with me on my new journey leading forward.''
Snyders is yet to decide on his career path after swimming but wants to retain an association with the sport.