Danno “Dan” R. Monahan, Ph.D., age 85, of St. Louis, Missouri, passed away on Friday, September 25, 2026. Born on August 6, 1941, in St. Louis to Richard and Leona Monahan, Dan was a lifelong scholar, educator, athlete, and avid reader.
He earned his B.S. from Washington University in 1964, a pivotal time where he not only played college football but also met his future wife, Judy. He followed this with an M.S. from Southern Illinois University Edwardsville in 1967, and a Ph.D. in History and Education from St. Louis University in 1972. Dan spent his career bringing the past to life for his students, focusing on World and U.S. History, particularly AP U.S. History. He taught for 25 years at St. Louis University High School (SLUH), having previously taught at Riverview Gardens High School (1966–1980) and Hancock High School (1964–1966). His dedication to his students extended well beyond the classroom, as he also spent years shaping young athletes as a high school wrestling, football, and basketball coach.
Known for his very dry sense of humor, Dan was passionately devoted to reading. He consumed history, current affairs, politics, science fiction, and fiction right up until his passing. His love for literature extended to others through his lifelong habit of donating books to various libraries and organizations. Drawing on historical figures like Abraham Lincoln and Winston Churchill, Dan constantly wove the past into daily life to teach the value of tenacity. He instilled a core belief in grit—the understanding that success is rarely a straight line, and that setbacks are merely chapters you fight through to get to where you want to be.
He leaves behind a legacy of resilience, intellectual curiosity, and quiet strength. Dan is survived by his beloved wife of 59 years, Judy; his son, Derrick, and his wife, Melinda; his daughter, Christina; his brother, Kevin, and his wife, Debbie; and his cherished grandchildren, Olivia and Mackenzie. He is also survived by a host of loving nephews, cousins, and close friends. He was preceded in death by his sister, Maureen, and his parents, Richard and Leona.
The family will honor Dan’s memory with a private Celebration of Life at his favorite restaurant.
Because of his profound love for reading and education, the family requests that, in lieu of flowers, memorial contributions be made to the St. Louis County Library Foundation. Donations can be made via their online Make a Gift portal, or checks made payable to the St. Louis County Library Foundation can be mailed to:
St. Louis County Library Foundation 1412 S. Spoede Rd. St. Louis, MO 63131
Judy, Derrick and Christina, Please know that you and your families are in my thoughts and prayers. I worked with Dan for many years at SLUH. We had some great times and memories. An outstanding teacher and coach, and a true scholar.
After seeing Dan in the hall or faculty room, he always had me laughing.
Dr. Monahan was one of my favorite teachers at SLUH (Class of 1982). When I read “known for his dry sense of humor,” it brought a smile to my face. How true!
He had such a great style as he walked up and down the rows – engaging all of us. Brilliant man – one of the best!
Absolutely my favorite teacher – no question. He helped foster my life long love of history. Also being friends with his nephew Ryan, I got the pleasure of spending a few moments with him after graduating SLUH, which were some of the funniest conversations I was blessed to be a part of. Thanks for everything, Doc. My condolences to the Monahan clan.
What a wonderful man : educator, coach, faculty member,
friend. Dan-O did so well in so many different areas. He made so many of us smile so ofter. May he rest in peace.
Please note that you are in my prayers. Dan was with us in the Social Studies Department at SLUH for many years and he was a special teacher and coach, one with a passion and love for teaching and learning. He will be missed. God bless all of you in your time of grief..
My sincere and prayerful condolences to all in Dan-o’s family and friend list. It was an honor to be a teacher-colleague of his at SLUH and recipient of his famously dry humor. May he rest in peace.
I was so sad to hear this. He was an incredible teacher at SLUH, and I was lucky to have taken his U.S. history class junior year. My prayers go out for your entire family.
Judy, Derrick and Christina,
I am so sorry for your loss. Dan was my first mentor in teaching and remained a huge influence in how I taught history throughout my career. He was kind, generous and a brilliant teacher. God bless Dan and your family during this time.
Doc was my US History teacher my junior year. He was very knowledgeable and I thoroughly enjoyed his classes. I even still have my notebook from his class where I used to write down his humorous quips. My favorite Doc quote was right before he returned our exams and would say “Boys, you are not getting into Harvard with these grades”. I had much better understanding of our country’s history from Doc.