Sean Patrick O’Sullivan ’87

Sean died Dec. 28, 2025. He is remembered for his dry sense of humor, admiration of nature, and most importantly, his love for family.

He was born in Niskayuna, N.Y., and raised in Clifton Park. His family hiked and camped in the Adirondacks. He excelled in sports. At Shenendehowa Central High School he had the first in-game dunk in school history.

Sean majored in chemical engineering, belonged to Cottage, wrote for The Daily Princetonian, and played basketball. He loved Reunions. He was often photographed wearing his favorite Princeton basketball polo.

Sean spent 20 years at Colgate-Palmolive, where he patented a method for dispensing toothpaste. He earned his MBA at Cornell and then moved to Acton, Mass., to work at Welch’s.

Sean met his wife, Deanne, at Colgate, flirting over exchanging a computer. They traveled extensively, often involving golf. His family lessons ranged from fixing the car to explaining parabolas to his fourth-grader. Sean loved playing and watching sports, reading, historical documentaries, and leading Bible studies.

Sean fought inclusion body myositis for 15 years, always saying he was blessed. Those around him knew he loved them and how lucky he felt.

Sean is survived by Deanne; children Caitlin, Sarah, Aidan, and Grace ’29; and four siblings.