Hiddink replaced Mourinho at Chelsea in December, but insists the former Real Madrid boss is the right man to bring the good times back to Old Trafford.
New Manchester United manager Jose Mourinho
After weeks of speculation, Mourinho signed a three-year deal to take over at Old Trafford last month - half a year after being sacked at Stamford Bridge, where he guided the Blues to their worst league start since 1979 last season.
Guus Hiddink took over from Mourinho at Chelsea following his sacking in December 2015
Despite the sour end to his second spell in west London, the hierarchy at United have been unable to hide their delight at Mourinho's appointment, with executive vice-chairman Ed Woodward even labelling him the 'best manager in the world'.
There is certainly no doubting the pedigree of the Portuguese, who during his glittering managerial career has won league titles in his native Portugal, England, Spain and Italy, while also winning the Champions League twice.
Mourinho's appointment has excited many Manchester United fans
Such a record will excite everyone connected with Old Trafford, with United currently suffering their joint-longest title drought since their breakthrough championship of 1993.
However, Hiddink, who replaced Mourinho at Chelsea following his dismissal in December, is convinced the Red Devils have got the right man in place.
Mourinho will hope to put at disappointing second spell at Chelsea behind him next season
“Mourinho is a coach who can deliver a performance, a success, an instant success,” Hiddink told BBC 5 Live.
“The competition is tough in England especially, but big clubs have to be there in the top three, top four, always.”