Hannah Sinclair Cowley

Hannah Sinclair Cowley, 30, beloved daughter of Heather S. Cowley of Medfield and Steven M. Cowley and stepmother Amy H. Weiler of Wellesley, passed away peacefully in her sleep in Sandwich, Massachusetts, on Monday, June 8, 2026.

In addition to her parents, Hannah leaves behind her beloved and loving siblings, Dylan S. Cowley and his wife Hannah H. Cowley of Washington, D.C., Benjamin S. Cowley of Brighton, Massachusetts, and Caroline S. Cowley, of Wellesley. Hannah is also survived by her adoring grandmothers Ann Sinclair of South Windsor, Connecticut and Gail Cowley of Trumbull, Connecticut, as well as numerous aunts, uncles and cousins. She will be deeply missed by all.

Hannah was born in Newton, Massachusetts on November 1, 1995, and grew up in Wellesley until leaving for Clemson University in 2015. Hannah graduated with honors from Clemson in 2019 with a B.S. in Marketing. Soon after, Hannah headed South again to Atlanta, Georgia, to work as a project manager in the communications group of WestRock (later Smurfit Westrock). Here she found herself happily sharing a new home city with her long-term boyfriend Thomas Hartsock, brother Dylan and soon-to-be sister-in-law Hannah.

Hannah and Thomas married in May 2024 and moved to Charleston, South Carolina in February 2025. Hannah returned to Wellesley later in 2025 and was considering options for future direction when she passed unexpectedly and far too soon.

Hannah’s greatest pleasures and interests were the simplest in life. Time with family and friends, reading, music, and taking advantage of the beauty outdoors, whenever and wherever the temperature was right. Hannah did not meet a beach she did not love, or an ice cream shop she would not try, and she treasured her time with her devoted golden retriever, Finley.

From a young age Hannah lit up every room she entered. Her beauty, intelligence, grace, tenacious spirit, creativity, flare for fashion, fierce wit and her deep love of family and friends touched all who had a chance to know her and will leave an impact that will endure far beyond her brief years.

A memorial gathering to honor Hannah will be held on Thursday, July 16, 2026, from 3pm to 6pm at The Garden at Elm Bank, Hunnewell Building, 900 Washington Street, Wellesley, Massachusetts. We welcome family and friends to come together to share memories and celebrate Hannah’s life.

In lieu of flowers, the family suggests a memorial donation to MEDA, Multi-Service Eating Disorders Association - https://www.medainc.org/donate.