Sioux Falls school principal dies following bout with acute myeloid leukemia
Memorial Middle School community mourns loss of longtime educator Demi Moon
Memorial Middle School announced in an email to student families the passing of Principal Demi Moon.
“It is with deep sadness that I share the news of the passing of Memorial Middle School Principal and friend, Dr. Demi Moon, who passed away on Sunday, May 31, 2026, after a courageous battle with cancer,” wrote Josh Siegfried, Assistant Principal of the Sioux Falls School District school. “Dr. Moon was a dedicated leader at Memorial Middle School and a valued administrator in the Sioux Falls School District.”
The District announced in spring 2025 that Moon had been diagnosed with acute myeloid leukemia.
She was a wife and mother of four, according to her social media. She previously worked as director of middle school curriculum and K-12 ELL (English Language Learner) services for the Sioux Falls School District.
“She was known for always putting students first and for leading with determination, resilience, and compassion. When I think of those qualities, I picture Dr. Moon’s smile and her unwavering commitment to the students, staff, and families she served,” Siegfried said.
“She has been, and will continue to be, a role model for our school community. Dr. Moon’s impact on Memorial Middle School is immeasurable, and she will be greatly missed by all who knew her.”
One doesn’t have a BOUT with cancer and pass away. They have a BATTLE. My sympathy to Ms Moon’s family, co-workers, and students. Her building won’t be the same for a very long time.