The England Under-17 international will join the Anfield Club for an initial fee of £1.7million and will join the club on 10 May.
“His signing is part of our long-term strategic recruitment plan,” Liverpool managing director Christian Purslow told the club’s official website.
“Jonjo is an exciting young England international. We all look forward to welcoming him to Melwood [Liverpool’s training ground].”
“It’s with the greatest reluctance that we have accepted an offer for Jonjo from Liverpool,” said Charlton plc chairman Richard Murray.
“No club likes to lose such a talented prospect, but the overall package is one we couldn’t refuse, and one which was very attractive to Jonjo.
“As a club, we have never stood in the way of any of our young players moving to ‘bigger’ clubs, and this also applies to Jonjo.
“Liverpool are going to develop him over the next few years to be a top player, and I can’t think of a better place for him to go.”
