The midfielder claims the award after a stellar past campaign as Reds captain that saw him lift the Premier League, FIFA Club World Cup and UEFA Super Cup.
Henderson was determined winner of the accolade after votes from supporters were combined with nominations from the club's official former players association, Forever Reds.
He pipped Sadio Mane to first place in the results as Trent Alexander-Arnold finished in third.
The No.14 made 40 appearances for Jürgen Klopp's side in all competitions throughout 2019-20, scoring four goals and registering five assists in the process.
Though his season was brought to a premature end due to a knee injury, Henderson was still able to become the first Liverpool skipper in three decades to lift the top-flight crown, before the team went on to secure a club-record points total of 99.