More than 14,000 new members have joined the party since the General Election was called, while more than 50,000 people signed up after the EU referendum last year.
The anti-Brexit party reached 101,832 members on Tuesday afternoon, eclipsing the previous record high of 101,768 party members it achieved in 1994.
The Lib Dems have seen a huge surge in membership numbers in recent weeks
The news will be welcomed by Lib Dem leader Tim Farron, who pledged to increase party membership to 100,000 by the end of this Parliament, which was due to be in 2020.
Mr Farron said: “We are going into these local elections bigger than ever before, with a clear message and a growing sense of momentum.
“You don’t need to agree with us on everything to agree that Britain needs a strong opposition to fight for you and your communities against Tory cuts to our schools, our NHS and our social care services.
Snap election: Politicians hit the campaign trail Tue, May 2, 2017
Politicians vow to change course of the upcoming snap election
AFP/Getty Images 1 of 31
Nicola Sturgeon, accompanied by Banff and Buchan candidate Eilidh Whiteford, visits the May Day event at Turriff in northwest Scotland on May 1, 2017, ahead of the June 8 general election
“In county halls just as in Westminster, Liberal Democrats are that strong opposition that Britain needs.”
The news comes as the centrist party prepares to take on the Tories in constituencies across the country in a bid to block a hard Brexit.
Appearing on The Andrew Marr Show on Sunday, Mr Farron shocked viewers when he admitted he harbours some eurosceptic views.
The Lib Dems are hoping to add to their nine MPs
He said: “I don’t want to go down a little bit of a rabbit hole here but you will remember that I resigned from the Liberal Democrat from bench about 10 years ago because I am a bit of a eurosceptic.
“I am somebody who challenges people in power, the EU, the government in councils.
“But I am somebody who believes Britain is better off in the European Union.”
The Lib Dem leader reiterated that he was the only option for the British people to oppose the Conservatives as he argued the Labour Party was “going backwards”.
He said: “I think people around the country are beginning to realise is a Conservative majority are not in question but a Conservative landslide means they will take you for granted wherever you live.
The Lib Dem campaign bus is set to travel across the UK as they try to boost their election hopes
“I want people to realise when they vote for the Liberal Democrats, they are not voting for a proxy or for anything else, they are voting for the Liberal Democrats plan.
“We are the only people not walking away. Jeremy Corbyn appears to be fighting the next Labour leadership election.
“Britain desperately needs a strong decent opposition for the sake of democracy.”