A graduate of Randallstown High and the University of Baltimore, Holley led the Millers to 123 wins and the past four Baltimore County championships. Friends, which competes in the Maryland Interscholastic Athletic Association B Conference, went 4-20 under coach Bill Pace last season.
While he described leaving Milford Mill "bittersweet," Holley said he was looking forward to the new challenge at Friends.
"Milford Mill was the school that gave me an opportunity and I'll be forever grateful. It allowed me to grow and put me in a position to move forward with this opportunity. My time at Milford Mill was valuable and prepared me for this opportunity," he said.