The R's took the lead just four minutes before the break, with Heidar Helguson netting from the spot after Adel Taarabt was brought down by Jay McEveley in the box. Rangers doubled their advantage on 53 minutes, after Jamie Mackie slid home from close range when Luke Steele failed to hold Hogan Ephraim's cross.
Taarabt added a third with a penalty ten minutes later after Helguson was felled by Nathan Doyle in the area, before Hall nipped in at the back post following Ephraim's dangerous, low cross on 81 minutes to cap off a perfect start on the opening day for Rangers.
The Hoops handed league debuts to no less than five players in a 4-2-3-1 formation, while Taarabt also made the QPR starting line-up following his permanent switch from Tottenham Hotspur.
Paddy Kenny was in goal for QPR.
In defence, Bradley Orr and Clint Hill took up the full-back positions, with Captain Hall and Kaspars Gorkss in the centre.
Shaun Derry and Alejandro Faurlin featured in defensive positions in midfield, with Ephraim, Taarabt and Mackie deployed in more advanced roles. Icelandic striker Helguson led the R's attack.
As the rain lashed down on a lush Loftus Road playing surface, Rangers were out of the traps fastest and fashioned the first effort of the half.
Faurlin smashed an effort over the bar following Gorkss' knockdown from an Orr free-kick.
Play then switched to the other end, and Stephen Foster was unlucky not to find the target when he headed goalwards McEveley's dangerous, in-swinging corner from the right.
The match had started at a frantic pace, and Rangers turned it up a notch more just moments later.
Mackie thought he was through on goal following Hill's ball at deep that looped over the Tykes' defence, before Jason Shackell came across to knock the ball out of play for a corner.
From the resultant set-piece, Rangers should have taken the lead.
Taarabt's corner from the left bounced up off a Barnsley defender, and when Ephraim nodded the ball back across the face of goal, Helguson somehow headed over from six-yards out.
Soon after, Taarabt came closest yet when he picked up a ball from deep, before he drove at the Tykes' defence and unleashed a ferocious, low drive from 25 yards that was tipped wide by Steele.
Moments later, Barnsley came within inches of opening the scoring when Andy Gray touched the ball to Hugo Colace on the edge of the box, who saw his driven effort whistle just past the left-hand upright.
Steele was soon called into action once again at the other end, however, and after Ephraim squared the ball to Taarabt 25-yards out, the Moroccan magician forced the Reds keeper into a fine diving save to his left, before the ball was cleared away up field.
Five minutes before the break, Taarabt was again involved - and this time his trickery earned the R's a penalty.
Neat, intricate passing play between Faurlin and Ephraim saw the latter feed Taarabt, before he drove into the penalty area.
Taarabt beat two men before attempting to pass a third, McEveley, who brought down the defender, leaving the referee with no option but to point to the spot.
Helguson stepped up to take the penalty and remained coolness personified to slide the ball home into the bottom right-hand corner and give the R's a half-time lead.
Intent on finding a goal to draw level, Barnsley came out for the second period in positive mood and only a minute had passed on the clock before they almost did just that.
Half-time substitute Iain Hume played the architect, laying the ball across the edge of the penalty area and into the path of Goran Lovre, whose smashed effort came back off the post before hitting Orr and going out for a corner.
Soon after, the R's were back on the offensive. Hill broke down the left before crossing on to the head of Mackie, whose weak effort went straight at Steele.
Mackie was not to be denied at the second time of asking, however, and on 53 minutes he doubled the R's lead.
Lovely passing play from Faurlin and Ephraim eventually saw the latter find space before sending in a low cross from the left.
Steele looked to have Ephraim's centre covered, before he let the ball slip into the path of Mackie, and the former Plymouth Argyle attacker slid in the divert the ball into the back of the net from close range.
Ten minutes later - and QPR found a third goal to almost certainly seal the points.
Doyle's mistimed challenge in the box saw him clip the heels of Helguson, and when the referee pointed for a second penalty kick, this time Taarabt stepped up to side-foot the ball into the right-hand corner.
And if the points weren't already safe, they surely were on 81 minutes.
Faurlin and Ephraim combined - not for the first time - before the latter sent over a teasing cross from the right and into the area.
The ball flashed across the face of goal before finding Hall at the back post, who slid home number four for the Hoops.