Mullen has turned to Bob Caton to take over its boys basketball program.
The school announced the hire in a press release on Wednesday morning.
"Bob's a legend and his reputation speaks for itself," Mustangs athletic director Vince Massey said in a statement.
Caton, a longtime head coach, stepped down from Highlands Ranch after the 2014-15 season. He has been a coach for 37 years, and has 505 career wins. He has the 11th-most wins in state history.
"I wanted to get back into coaching, and this worked out great," Caton said in a statement.
Aside from Highlands Ranch, Caton has also had stops at Manual, Denver West, George Washington and Aurora Central.
Mullen went 8-16 last season in the Class 5A Centennial League, and hasn't had a winning season since 2007-08. Caton replaces Peter Spiessbach, who went 22-49 in three seasons.
"I think there will always be a certain degree of talent here," Caton said. "What they do well, I will put them into that position. And it has always been a good league."