Facing a daunting 3-0 deficit after last week's first leg, Origi made light of Mohamed Salah and Roberto Firmino's absence from the Liverpool forward line by poaching a seventh-minute opener on Tuesday.
Jurgen Klopp's side kept the contest at a pace frenetic enough that Barcelona were rarely allowed to settle and Wijnaldum's quickfire brace before the hour had the locals in raptures.
It was a night for unlikely heroes and Trent Alexander-Arnold's quickly taken corner allowed Origi to smash high into the net 11 minutes from time – inflicting a humbling upon LaLiga champions Barca and the great Lionel Messi even more punishing than their surrender at Roma in last season's quarter-final.
Liverpool's remarkable 4-3 aggregate triumph means a June 1 final against Ajax or Tottenham - and the chance to right the wrongs of last season's fall to Real Madrid at the last hurdle - awaits.
— Liverpool FC (@LFC) May 7, 2019
Shortly after Clement Lenglet's timely touch prevented Jordan Henderson from turning in Xherdan Shaqiri's low cross, the Reds captain drove into the Barcelona box and Marc-Andre ter Stegen could only push a tame shot to the feet of the waiting Origi.
Alisson saved sharply from Messi and Philippe Coutinho as Barca began to click into gear, with Ter Stegen's 24th-minute stop from Andy Robertson of a more unorthodox variety.
Liverpool's goalkeeper intervened crucially in first-half stoppage time to deny Jordi Alba after Messi sliced the hosts open on the break.
Unlikely hero Wijnaldum entered the fray in place of the injured Robertson at half-time and Liverpool resumed on the front foot, Ter Stegen repelling Virgil van Dijk's instinctive backheel volley from Alexander-Arnold's cross.
Alisson was also back into his work as Suarez sprung the Reds' offside trap – a stop that looked even more vital when Wijnaldum drove Alexander-Arnold's next delivery from open play through Ter Stegen's grasp.
Barcelona were rocking, with memories of Rome – where they crashed out after holding a 4-1 first-leg lead - flooding back as Wijnaldum rose highest to emphatically convert Shaqiri's 56th-minute centre.
Where Barca minds were muddled, Alexander-Arnold's was razor sharp and Origi pounced to leave Messi and his team-mates battered, bruised and beaten.
What does it mean? Reds have six appeal as Messi's dream dies
Vincent Kompany's spectacular winner for Manchester City against Leicester City on Monday left Liverpool staring at somehow ending 10 months of relentlessly high quality without a trophy.
Now they are one game away from claiming their sixth triumph in Europe's biggest competition, while Messi's wait for his fifth goes on.
This will be even more painful than the defeats to Atletico Madrid, Juventus and Roma that followed Barcelona's last success in 2015.
THIS TEAM pic.twitter.com/L5llXLuuzq
— Liverpool FC (@LFC) May 7, 2019
Wijnaldum writes his own famous Anfield chapter
A club and a ground steeped in great European deeds, Wijnaldum was perhaps not the man expected to add his name to Liverpool folklore. But his two goals in the space of 122 delirious second-half seconds provided those in attendance with memories they will never forget, as one of the unsung heroes of Liverpool's campaign emerged from a form slump to enjoy a deserved moment in the sun.
Coutinho disappears in a hail of boos
Anfield predictably did not look fondly upon its two former sons, with Brazil midfielder Coutinho coming in for heavier stick than Suarez, despite the latter frequently being keen to show his appetite for the dark arts remains. Aside from his first-half chance, the game passed Coutinho by and he made way shortly after Wijnaldum made it 3-0, not to be trusted with turning the tide. He failed to create a single chance in his one-hour outing.
Photo: Getty Images. Caption: Liverpool midfielder Georginio Wijnaldum