Dennis John Martin, 71, of Sewickley passed on Saturday, February 20, 2021. Dennis was a devoted husband to Jacqueline J. Martin (Valenty), and loving father to Michele Russo, Michael (Karen), Matthew (Lisa), Mark (Lisa), Dennis, Melissa Molitor (Derek), John (Kelsey), Joe (Kyleigh), Adam, Erin (Mike), Meghan, and Robert. The best grandfather to Anthony DaBiero and Abbey Russo, Teagan and Morgan Martin, Nicholas and Mia Martin, Lydia Martin, Doak, Rowan, and Bodhi Molitor, Jack and Emmett Martin, Liam, Eli and Emma Martin, and Olivia Schatzel. And great grandfather to Jack and Hanna DaBiero. Brother to Gretchen Mahoney of Pittsburgh, PA, Jerome Martin of Novi, MI and Barbara Cook of Sewickley, PA. Preceded in death by man’s best friend by Winston and survived by Apollo. Dennis grew up in Wexford, PA, living in numerous cities including New York, VA Beach and Harrisburg, and the New River Gorge area, before residing in Sewickley, PA for the remainder of his life. As a loyal employee, he worked for American Bridge Company for over 30 years. He shared his love for baseball and his community by being a dedicated coach, mentor, and volunteer for St. James Catholic School and the Quaker Valley Recreation Association. Family and friends will always remember his beautiful smile, great laugh, sense of humor and quick wit. Visitation will be held on Tuesday at Copeland Funeral Home, 702 Beaver Street, Sewickley from 2 - 4 pm & 6 – 8 pm. A Funeral Mass will be held on Wednesday at St. James Church, 200 Walnut Street, Sewickley on Wednesday at 10:30 am (EVERYONE PLEASE MEET AT CHURCH). Burial will be private. In lieu of flowers, contributions may be made to the MPN Research Foundation, 180 N Michigan Avenue, Suite 1870, Chicago, IL 60601 for Myelofibrosis Cancer research.