The venue, home to BT Convention Centre and Echo Arena, will stage its annual autumn conference in September 2014, which is likely to attract more than 7,500 attendees.
In 2008, the Lib Dems held their spring conference in Liverpool, returning two years later, in September 2010, for their main gathering, which was the first ever major party political event held at the waterfront venue.
Bob Prattey, chief executive of ACC Liverpool, said the return of the Lib Dems was the result of ACC Liverpool’s previous track record to deliver and years of building up a relationship with the party conference organiser.
He added: "Lib Dems coming to us for a third time is further confirmation that Liverpool is stronger than ever as a conference destination. Each time, the economic impact benefit for the city was terrific and we received positive feedback from delegates about the venue and the city."
Nick Clegg, deputy Prime Minister and Liberal Democrats leader, was joined in the city by 6,000 delegates and 1,600 global media last year. The event generated £10m for the city economy with 206 fringe meetings hosted at ACC Liverpool and around 300 additional fringe meetings taking place elsewhere in the city.
ACC Liverpool hosted the Labour Party Conference in September last year, which saw 11,000 delegates descend on Liverpool, delivering a £15m boost to the city economy.
The Labour Party Conference saw maximum security procedures implemented and rigorous plans put into place in collaboration with Merseyside Police, Liverpool Convention Bureau and Liverpool City Council.