William M. Cassidy

William Cassidy, a proud Irishman, devoted husband, father and grandfather, and successful small business owner, passed away leaving behind a legacy of hard work, family, and dedication to those he loved.

Born in County Louth, Ireland, William immigrated to Chicago in the early 1960s, bringing with him the determination and strong work ethic that would define his life. He was a proud member of Local 150 for nearly 60 years and owned and operated his own small business.

William shared a wonderful life with his beloved wife, Eileen O'Brien, who preceded him in death in 2018. Together, they raised four sons: William (Dina), Allen (Ann), Robert (Colleen), and Bruce (Elizabeth).

He was a proud grandfather to Connor, Morgan, Jack, Kendall, Olivia, Brody, and Jacqueline, who brought him great joy and continued his family's legacy.

Following Eileen's passing, William was fortunate to find love and companionship again with Carol Lyons during the final years of his life, bringing him happiness and comfort.

William is survived by his two sisters, Joan Croxdale of Seminole, Florida, and Josie Flynn of Dundalk, Ireland. He was preceded in death by his nine siblings. Michael, Audrey, Maura, Gerard, Olive, Katie, Rosie, Jim and Anthony

William and Eileen shared a love of travel and adventure, making it their goal to visit every state in the United States. Together, they accomplished that goal except for Hawaii, creating memories that would last a lifetime.

William will be remembered for his Irish roots, strong work ethic, entrepreneurial spirit, and, above all, his devotion to his wife and family. His life was a testament to love, perseverance, loyalty, and the importance of family. He leaves behind a legacy that will live on through his children, grandchildren, and all those who had the privilege of knowing him.

Visitation

Saturday, November 14, 2026

11:00 a.m. - 3:00 p.m.

Kurtz Memorial Chapel

65 Old Frankfort Way

Frankfort, IL 60423

Kurtzmemorialchapel.com

Memorial Donations

In lieu of flowers, donations may be made in William's memory to either of the following organizations:

● Northwestern Medicine Foundation: Donate to Northwestern Medicine Foundation
https://www.nm.org/about-us/foundation?utm_source=chatgpt.com

● American Heart Association: Donate to the American Heart Association
https://www.heart.org/en/get-involved/ways-to-give?utm_source=chatgpt.com