John DeSio was named assistant women's basketball coach at Mercy prior to the 2006-07 season. His responsibilities include assisting head coach Ashlee Kelly with the day-to-day operation and management of the program, on court coaching, recruiting, and community service projects.

His most recent coaching experience came at New York City College of Technology. He was an assistant coach for the women's basketball team from 2004-06. DeSio was the head recruiting and retention coordinator for the program. In the 2004-05 season the team went 12-12 overall, including a 7-6 mark in the CUNYAC, and was the South Division Runner-up.

DeSio also has collegiate experience as the head men's junior varsity coach at Fordham University from 1996-2000. At Fordham he worked alongside Bob Hill, who is currently the coach of the Seattle Super Sonics and a former coach of the New York Knicks, Indiana Pacers, and San Antonio Spurs. DeSio was the recruiting liaison between the varsity team and junior college and prep school students.

DeSio has served as the girl's junior varsity coach at Curtis High School, going undefeated on Staten Island and winning three championships from 2001-03. DeSio also possesses vast experience at the AAU level. In 1995 he became the head coach of the Queens Lady Magic program. In 1997, DeSio coached the first New York City Parks and Recreation 14 and under team, winning the City Championship. He has also participated in the Nike and the Canadian/American coaches clinics.

DeSio, is a 1973 graduate of New York Police Academy. He is a retired police officer after 25 years of service. In 2004, he earned his Bachelor of Science degree in Community and Human Services from SUNY-Empire State College. He is currently pursuing a Masters of Sports Psychology from Capella University. He and his wife Marcella reside in Staten Island, New York.