Hoilett put the visitors in front in the 43rd minute with a well-executed shot after Wanderers' David Davis had only been able to flick on a throw into the box from Rovers midfielder Morten Gamst Pedersen.
The Canadian forward then fired in a second from 25 yards in the 69th minute, clinching a result that moves his team up from 18th to 16th in the table, three points clear of the relegation zone, and leaves the hosts 19th, one adrift.
Wolves, playing at their own ground for the first time since the humiliating 5-1 derby loss to West Brom a month ago which proved to be Mick McCarthy's last game in charge, were looking to put a turbulent few days firmly behind them but failed to rise to the occasion.
The Midlands outfit have now won only once in their last 14 league games and the match finished with some of the home supporters calling for the club's board, who decided to dismiss McCarthy and replace him with his assistant Terry Connor, to be sacked.
There had been a similar protest outside the stadium ahead of kick-off.
Connor made four changes from the thumping 5-0 defeat at Fulham last Sunday, with top-scorer Steven Fletcher - fully recovered from illness - Sebastien Bassong, David Edwards and top-flight debutant Davis coming in for the injured Karl Henry and benched trio Michael Kightly, Kevin Foley and Christophe Berra.
Roger Johnson, punished earlier in the week after reporting for work unfit to train properly, was once again among the substitutes, while for Blackburn Jason Lowe returned from suspension and Marcus Olsson joined his twin brother Martin in the side, replacing Bradley Orr and Radosav Petrovic in the only adjustments from last week's 1-1 draw with Aston Villa.
Wanderers made a bright start, with Kevin Doyle sending an early header off-target, but at the other end, Ayegbeni Yakubu volleyed over and then struck at goalkeeper Wayne Hennessey from Mauro Formica's cross after the hosts had given away possession.
Moments later Yakubu was on the end of another Formica delivery to head narrowly wide, before Wolves winger Matt Jarvis put the ball the wrong side of the post from close range, Edwards' cross appearing to come at him a little too quickly.
Fletcher tried his luck from distance in the 27th minute but his effort was nowhere near troubling Paul Robinson in the Blackburn goal.
Yakubu slid in a failed attempt to convert Marcus Olsson's cross, but the wideman had already been flagged offside, and the Nigerian then shot over from a tight angle.
Rovers were finishing the half strongly and made the breakthrough two minutes before the break as Pedersen's throw was diverted by Davis' head into the path of Hoilett, who sent the ball bouncing past Hennessey.
Two minutes into the second period Fletcher looked to emulate Hoilett but miscued his volley from Jarvis' cross.
Blackburn were soon back on the attack and Pedersen swung in a delivery that was too deep for Formica to fashion anything with.
Wolves lost the ball again, allowing Formica to send a shot down Hennessey's throat and Davis then did well to nick the ball off Yakubu as the striker tried to turn in the box.
The pressure was mounting on Wanderers and with just over 20 minutes to go Rovers doubled their advantage, Hoilett finding the space to lash the ball in from outside the area.
Wolves needed to respond quickly and after surviving a scramble in their box from a corner, they applied some pressure, only for Davis to skew wide in a useful position.
Robinson kept out a shot from Jamie O'Hara and Fletcher and substitute Nenad Milijas - on for Davis - missed the target with headers.
Ultimately it was too little too late, and after Robinson saved a further Fletcher effort, there were boos at the final whistle from Wanderers fans, with banners being unfurled in the stands expressing their anger at the board.