Obituary
Guest Book
Gary W. O'Sullivan, born on August 15, 1945, in Queens, NY, passed away peacefully on October 27, 2025, in Deer Park, NY. He was a cherished husband, father, grandfather, brother, and friend to many.
His Type A personality, paired with his selfless nature and opinionated charm, often filled the room with laughter and joy. He had a remarkable ability to find humor in everyday moments, leaving those around him with fond memories of shared jokes and warm conversations. Raised in Seaford, Gary cultivated a love for classic cars, boats, and fishing. His passion for automobiles once led him to own a Maaco auto body shop, reflecting his deep appreciation for the art of car restoration. This devotion to his hobbies was a testament to his spirited and adventurous character.
In addition to his enthusiasm for life, Gary is remembered for his steadfast love and devotion to his family. He was married for 40 years to Joanne, who he loved deeply. Together, they nurtured a beautiful family that includes their daughters, Kimberly Acquista and her husband Joseph, and Karen Seifert and her husband Justin. Gary was also a proud grandfather to Emily, Ana, Mia, Nicholas, and Joseph, whose lives he filled with encouragement and laughter. Loving dog Dad to Kiley. He is survived by his loving wife Joanne, daughters Kimberly and Karen, grandchildren, and his brother Richard O'Sullivan. Gary was preceded in death by his parents, Timothy and Anita O'Sullivan, and his brother Edward.
Visitation will be held on Wednesday, October 29, 2025, from 2:00 PM to 7:00 PM at the Mangano Family Funeral Home in Deer Park, NY. A Mass will be celebrated in his honor on Thursday, October 30, 2025, at 11:15 AM at Saints Cyril & Methodius R.C. Church, also in Deer Park.
Gary W. O'Sullivan leaves behind a legacy of love, laughter, and unforgettable memories. His presence will be dearly missed, but his spirit will continue to shine in the hearts of those who knew him.
IN LIEU OF FLOWERS THE FAMILY ASKS THAT YOU PLEASE DONATE TO ALZHEIMER'S:
https://events.alz.org/fundraisers/kimberlyacquista/gary-w--o--sullivan---a-celebration-of-life?utm_source=qr&utm_medium=print
To plant trees in memory, please visit the Sympathy Store.
1701 Deer Park Ave, Deer Park, NY 11729
Memories and condolences can be left on the obituary at the funeral home website.


What kind of arrangement is appropriate, where should you send it, and when should you send an alternative?
Read more
We'll help you find the right words to comfort your family member or loved one during this difficult time.
Read more
Information and advice to help you cope with the death of someone important to you.
Read moreIf you’re in charge of handling the affairs for a recently deceased loved one, this guide offers a helpful checklist.
Read more
Legacy's Linnea Crowther discusses how families talk about causes of death in the obituaries they write.
Read more
You may find these well-written obituary examples helpful as you write about your own family.
Read more
These free blank templates make writing an obituary faster and easier.
Read more
Some basic help and starters when you have to write a tribute to someone you love.
Read more