The 19-year-old forward, who can play on either flank, joined Liverpool's academy at the age of eight but is yet to make his senior debut.
The Reds did not disclose the length of Wilson's new contract on their official website.
A club statement read: "Liverpool can confirm that Harry Wilson has signed a new contract with the club. The 19-year-old winger put pen to paper today."
While Wilson took to social media to announce his new deal, tweeting: "Delighted to have signed a new contract with @LFC, the hard work continues."
Wilson spent the first-half of last season out on loan at League One side Crewe, but made just seven first-team outings and saw his spell cut-short in Decemeber.
The once-capped Wales international became his country's youngest ever player in October 2013, making his first senior appearance as a 16-year-old.