Origi’s previous contract was set to expire at the end of the 2019/2020 season but the impressive performances he put in despite limited playing time in the last campaign have persuaded the European champions to secure his future at Anfield.
Origi joined Liverpool from French club Lille in the summer of 2014 and has also spent time on loan at German side Wolfsburg during his five years at Merseyside.
After signing his new deal, Origi told the Liverpool website: "I'm very happy to be able to sign this contract and it gives you a boost at the beginning of the season.
"I always felt comfortable here. I made steps during my career. I say that I became a man here at this club; I signed when I was 19.
"When we had to make the decision I just wanted to speak with the club first and my entourage, but the feeling was always that I wanted to stay and extend my contract.
"[I want] to keep progressing and trying to maximise the potential and talent I have each and every day. At the end of my career I want to sit back and be proud that I used all of my gifts and talents.
"I think the next years are going to be very special - prime years, maybe - and I'm going to try to use them to the fullest."
The new contract represents a surprising turnaround for Origi, whose Liverpool career looked set to be over last year and many Reds fans would have been forgiven for thinking he had already left the club.
But the forgotten man breathed some much needed life into his Anfield career when he climbed off the bench to score the winner on his first Premier League appearance of the season against Everton in the Merseyside derby last December.
Origi’s growing importance to Liverpool heightened when he took advantage of Mohamed Salah and Roberto Firmino’s absence in the Champions League semi-final second leg against Barcelona at Anfield to register two goals to help the Reds advance to the final.
The 24-year-old Belgian, whose father is a former Kenya international, cemented his place in Liverpool folklore with the insurance goal in a 2-0 win over Tottenham Hotspurs in the Champions League final.
Origi made 12 Premier League appearances last season, scoring three goals while he recorded another three strikes in eight Champions League appearances.