Dr. Lucius "Pete" Frederic Cassidy Jr.

Dr. Pete Cassidy was an incredible husband, father, grandfather, great grandfather and Orthodontist. He passed away on June 1st, 2022, in Highlands Ranch, Colorado from complications due to late stage Alzheimer’s disease.

He was born in Denver, Colorado, at Mercy Hospital. Pete was the only child of Dr Lucius Frederic Cassidy, Sr. and Helen O’Brien Cassidy. He grew up in Louisville, Colorado where his father was a mine Doctor followed by 50 years using their home for his family medicine practice.

Pete graduated from The Canon City Abbey high school and received his undergraduate degree from the University of Notre Dame. He received both his DDS dental degree and Masters Degree in Orthodontics, from St Louis University. After graduating from dental school, Pete served our country as a dentist in the Air Force at Davis Monthan Air Force base in Tucson Arizona, where he treated the flight crews and their families during the cold war.

He met the love of his life Mary Sherry, from Tulsa, Oklahoma, while in school in St Louis. They were married on October 31st 1954. After a brief stop in Chicago to practice orthodontics, Pete and Mary settled in Littleton, where he was one the first Orthodontists in south Denver. Pete had a thriving practice in Littleton for 40 years and was very happy and proud to have his son Mark, follow in his footsteps. They had fantastic time practicing together for 5 years starting in 1985.

He loved his yard, was an avid sports fan and tennis player, who played competitive tennis until he was 82, and a diehard Notre Dame and Denver Bronco football fan. He instilled his love of sports to his boys and rarely missed any of the boy’s football, basketball, baseball or lacrosse games.

Pete was very active in the Littleton community and many professional organizations. From St Mary’s of Littleton, Pony league baseball, the Greenwood Village parks, trails and recreation committee, the Greenwood Village City Council, The American Dental Association, the Metropolitan Denver Dental Society, The St Louis University Department of Orthodontics Alumni association, The American Association of Orthodontists, to being the head usher at St Thomas More Catholic Church for 15 years.

He was very social and led a very active life, with a true love for travel. He loved European river cruises, and had trips to China and South America, with his son Brian, that he loved to tell stories about and share pictures.

Pete is survived by his 3 sons: Dr. Mark Cassidy of Littleton, Colorado and his sons Bryan, Christopher and Andrew. Brian Cassidy (Loretta) of Phoenix, Arizona and their son Jackson. Tom Cassidy of Littleton, Colorado and his late son Michael and his children, Paige, Ryann, Erin, Drew and Beau, along with 5 great grandchildren, Hadley, Hope, Hazel, Harper and Leo. He was preceded in death by his wife Mary, oldest son Michael and grandson Bryan.

He was a true gentleman in every sense of the word and had a lasting impact on so many lives in the Littleton community, from his family, his friends, his patients, his tennis partners and the St Thomas More community. With his quick wit, firm handshake, penchant for storytelling and his desire to check everyone’s bite, he will be missed and never forgotten as a true Littleton legend.

The family would like to personally thank the Windcrest Community in Highlands Ranch, for the outstanding care they provided Pete, his last four years in memory care and the short time he was in skilled nursing, and Bristol Hospice for their compassion and care the last month of his life.

A Funeral Mass will be held Friday July 15th, 11:00am, at St Thomas More Catholic Church, 8035 S. Quebec St. Englewood, Colorado. A reception will be held at the church after the service, followed by interment At Olinger/Chapel Hill Cemetery, 6601 S Colorado Blvd. Centennial.

In Lieu of Flowers donations can be sent to United States Jr. Tennis Association or the St Louis University Department of Orthodontics in his name.