Cathro and Nuno originally met on an SFA coaching course in 2009, and the Scotsman went on to become Nuno’s assistant manager at Rio Ave in 2012.
There they enjoyed much success, including a sixth-place league finish, two cup finals and European qualification for the first time in the club’s history.
Nuno then took his assistant to Valencia, before Cathro left the Mestella for family reasons and took up a role as assistant manager at Newcastle United, before eight months managing Scottish Premiership side Heart of Midlothian.
Cathro met the first team squad at Compton on Wednesday morning as part of the squad’s first day of pre-season training.
“I am very excited about joining Wolves and looking forward to working with a coach and staff I know, trust and believe in,” Cathro told wolves.co.uk.
“All of us share the same footballing philosophy and that is such an important factor for a successful coaching team.
“Wolves is a fantastic club with a rich history and lots of potential, and I can’t wait to get started.”