Mary Ella Costello

Mary Ella Costello, 85, of Cleveland, OH, passed away on Tuesday, April 7, 2026, surrounded by her loving family.

Mary was born on May 30, 1940, in Sharon, PA. She is the daughter of the late Harry and Leona (Slater) Markle and graduated from Sharpsville High School.

A dedicated homemaker, Mary was a highly talented seamstress, making countless family dresses, suits, and even Halloween costumes for her many grandchildren. She was also a skilled baker and cake decorator, with her cookies and pies being the highlight of every family holiday. We will all especially miss her buckeyes and clothespin cookies. She loved it most when her dinner table was crowded with family and friends. She enjoyed crocheting in her rocking chair while watching her game shows on TV. Mary was an avid fan of NASCAR, especially her favorite driver, Jeff Gordon. In her younger years, she found lots of joy in bike riding. She loved all of her animals over the years, but had quite a soft spot for her chihuahua, Tinkerbell.

Above all else, she was selflessly dedicated to her family, whom she loved with her whole heart. Mary married the love of her life, John (Jack) Paul Costello Jr., on August 6, 1962. They spent 60 wonderful years together before he passed away on June 25, 2023. Their house was adorned with countless family photos and memories of a life well lived. She was so proud of her family and saved all sorts of artwork and programs from school plays and concerts over the years. Mary made her house a safe place to land for all of her children and grandchildren and we will miss her so dearly. We take comfort in knowing she is reunited with Papa again (and surely back to keeping him in line!)

Mary is survived by her son, John P. Costello, III (Kimberly), of Berlin Heights, OH; her daughter, Tammy L. Denton (CS), of Stow, OH; eight grandchildren, JP Costello, IV (Bridgette), North Olmsted, OH, Terry Costello (Kourtney), Cleveland, OH, Xavier Denton (Liz), of Stow, Shelby Miller (Jimmy), Stow, Kyle Costello, of Cleveland, Trisha Brown (PJ), of Vermilion, OH, Michaela Ash (Shane), of Canal Fulton, OH, and Priscilla Kohler, of Port St. Lucy, FL; 13 great-grandchildren, Avery Denton, Irelynn, Brynlee and Riley Costello, Eliza Miller, Autumn Yontz, Greyson, Paislyn and Crew Brown, Kohlie and Luka Ash, Alyana and Ayven Hill.

In addition to her parents and beloved husband, Mary was preceded in death by a great-grandson, Javin Jaques; and six siblings, Robert, Bonnie, Sandy, Harry, Duane and Jim.

The family suggests memorial contributions be directed to the Greater PA Super Kids Classic, C/O Western PA and Eastern OH Community Foundation, 7 W. State St., Suite 301, Sharon, PA 16146.

Calling hours will be 11 a.m. to 1 p.m. Thursday, April 16, 2026, in J. Bradley McGonigle Funeral Home and Crematory, Inc., 1090 East State St., Sharon. 

Funeral service will be at 1 p.m. Thursday, in the funeral home, with Rev. Phil Cooper officiating.

Interment: Hillcrest Memorial Park, Hermitage.