Dennis O'Brien, 80, of Keshena, passed away on Tuesday, September 14, 2021, in Keshena. He was born on October 7, 1940, in Dubuque, Iowa to the late Cyril and Helen (Brown) O'Brien.  After he graduated from Dubuque Senior High School, he enlisted in the military in 1960 and served as a U.S. Paratrooper in the 101st Airborne Division. Dennis met Dolores Whitney in 1965 and they were united in marriage on June 13, 1966. Dennis worked as a millwright for many years and taught P.Y.D. workshop in Keshena. He built his own home in 1984. Dennis and Dolores were foster parents, and they dearly loved their children and grandchildren. He enjoyed motorcycles and took many Harley rides throughout the years. He was a wonderful man with a great sense of humor and will be dearly missed.

Dennis is survived by his children; Diane O'Brien, Michael O'Brien, and Kathleen (Eugene Jr.) Webster, his ten grandchildren; Dillon O'Brien, Dolores Garcia, Cheryl O'Brien, Tina Lyons, Evan Zeleznik (Milagros), Madeline O'Brien, Patrick C. O'Brien, Erin (Martin) Gonzalez, Paul O'Brien, and Michael O'Brien, 19 great-grandchildren; brothers and sisters; Paul (June) O'Brien, Cheryl Buelow, Deborah (Bob) Esser, Diane (John) Waychoff, Dawn (Tim) Henry, and Clarice Bell.

Dennis was preceded in death by: his wife, Dolores O'Brien; children, Barbara and Patrick; and a grandson, Trent.

Funeral services will be held at St. Michael Catholic Church in Keshena on Tuesday, Sept. 21, 2021, at 11:00 am. Visitation will be held at the O'Brien residence located at W2210 County Road M in Keshena beginning Saturday, Sept. 18, 2021, from 12:00 pm until the time of procession to the church.