Campbell topped the times in the 10-minute Hyperpole session for the fastest 10 cars that progressed from opening qualifying lasting 12 minutes.
The Australian posted a 1m39.347s aboard the #5 Porsche 963 on his final lap to pip Toyota driver Nyck de Vries and claim the first pole for an LMDh car in the WEC.
De Vries ended up on a 1m39.511s aboard the #7 Toyota GR010 HYBRID Le Mans Hypercar as the Japanese manufacturer continued its assent up the order since its disappointing showing in the pre-season Prologue test at the start of the week.
Callum Ilott ended up third on a 1m39.622s that briefly stood as the best time aboard the #12 Jota Porsche.
Antonio Fuoco took fourth for Ferrari aboard the #50 499P LMH on a 1m39.976s, just five hundredths ahead of the second Porsche Penske Motorsport entry in which Kevin Estre posted a 1m39.981s.
Peugeot rounded out the top six courtesy of a 1m40.067s from Jean-Eric Vergne in the #93 9X8 LMH.
Cadillac failed to live up to its form through the Prologue and free practice, Alex Lynn ending up seventh on 1m40.103s.
Antonio Giovinazzi was eighth in the second AF-run factory Ferrari, Jenson Button ninth in the #38 Jota Porsche and Stoffel Vandoorne 10th in the #94 Peugeot.
Brendon Hartley was bumped out of the top 10 in the dying moments of qualifying in the #8 Toyota.
Hypercar newcomers Alpine, BMW, Lamborghini and Isotta Fraschini also failed to progress into the Hyperpole session.
Pole position in LMGT3 when to TF Sport Chevrolet driver Tom van Rompuy.
The Belgian set two laps good enough for the top spot in the Hyperpole session in the #81 Chevy Corvette Z06 GT3.R, his best lap of 1m54.372s giving him an eight tenth margin at the front of the field.
Aliaksandr Malykhin jumped to second in the times right at the end of the 10-minute session with a 1m55.179s aboard the Manthey PureRxcing Porsche 911 GT3 R.
That demoted Thomas Flohr to third place in the best of the AF Corse Ferrari 296 GT3s.
The Swiss driver’s 1m55.182s was just two hundredths quicker than Clement Mateu in the D’station Aston Martin Vantage GT3.
The Heart of Racing's Aston took fifth in the hands of Ian James, ahead of Sarah Bovy in the Iron Dames Lamborghini Huracan GTE EVO2.
The Qatar 1812Km, which will run for no longer than 10 hours, begins at 11:00 local time on Saturday.
