Mark Eugene Klingler

Mark Eugene Klingler, born September 21, 1955, in Utah, and lately an O’Fallon, Ill. resident, passed away Friday afternoon, December 19, 2025 at John Cochran VA Medical Center, with family at his side. He was 70.

Born into a military family, he moved many times and lived in the United States and Japan as a child, but enjoyed his formative years in Santa Barbara, Calif., where the family settled. Upon graduating High School, he joined the United States Air Force and served both overseas and at Davis-Monthan Air Force Base, in Tucson, Ariz.

Following his time in the Air Force, he met the man he would eventually marry in 2012, Allen Kelley. They shared a mutual love of Tucson, Ariz., where Mark completed his education and eventually became an accountant. The two called The Old Pueblo home for over three decades.

Together, they were able to travel through Europe and Africa. Back home, they told stories to their families over many a holiday meal. When Mark’s father passed in 2001, Mark and Allen took care of Mark’s mother, Marion, until her passing in October 2005.

Following Allen’s passing in 2014, Mark continued to live in Tucson until 2018, when he moved to O’Fallon, Ill., to be with family.

Mark’s true legacy is his kindness to all people and love of family. Having no children of his own, Mark became the “doting uncle” to his fourteen nieces and nephews. He packed many adventures and acts of kindness and generosity into his life. A lifelong lover of fantasy literature, to quote Tolkien, his favorite author, “Embrace your simple life”, which he did.

Mark was preceded in death by his parents, Eugene and Marion, nee Dietz, Klingler, as well as his husband, Allen Kelley. Mark is survived by his brothers Chuck (Cathy), Bill (Karen), and Karl (Carol) as well as his sisters Kathy, Karen (Jim Heffern), and Linda (Mike Neal), his 14 nieces and nephews, as well as their children, many cousins, and friends throughout the world. He will be missed.

Online condolences may be shared at www.wfh-ofallon.com. Wolfersberger Funeral Home, O’Fallon, Ill., served the Klingler family.