The 37-year-old has been added to the Millers' backroom staff as they try to avoid relegation.
The 37-year-old had previously been an academy coach at fellow Championship strugglers Bolton Wanderers, and took charge of the Trotters for one game following Dougie Freedman's departure in 2014. But he explained that a move to the New York Stadium was an opportunity too good to turn down.
"I have been lucky enough to have worked as an academy coach with the under-21s at Bolton, but the opportunity arose to come here and create something which is very exciting," he said.
"I am honoured to have been chosen for the role, and to have the opportunity to help put in place a structure which will help the club develop some exciting talent.
"The role here will see me working closely with both the Academy and first team. It is an exciting project and it is a challenge that I am really looking forward to,” he added.
Hughes became a cult hero during his time at Elland Road, making over 100 appearances in the league, and being part of the side that famously went to Old Trafford and knocked Manchester United out of the FA Cup, despite being in League One at the time.
Despite perhaps not possessing the talent of some of his teammates, Hughes became one of the most popular players in Leeds' recent history due to his work-rate, and his willingness to feature in a range of positions for the side.
The move to Rotherham will see him link up with Neil Redfearn. The Millers manager was part of the backroom staff during the latter part of Hughes' time with the Whites, so he would have had a considerable understanding of what Hughes will bring to the role.
And if Hughes manages to instil the work-rate in the Rotherham players that he possessed throughout his playing career, then it seems unlikely that the club will be facing relegation come the end of the season.