On October 28, 2019, Williams was traded to the New York Giants for a 2020 third round pick and a 2021 fifth round pick.

In week 15 against the Miami Dolphins, Williams forced a fumble on former teammate Ryan Fitzpatrick which was recovered by teammate Sean Chandler during the 36–20 win.

On March 16, 2020, the Giants placed the franchise tag on Williams.
He signed the one-year tender on April 22, 2020.
He was placed on the active/non-football injury list at the start of training camp on August 2, 2020.
He was activated on August 14, 2020.
On October 28, 2019, Williams was traded to the New York Giants for a 2020 third round pick and a 2021 fifth round pick.
In week 15 against the Miami Dolphins, Williams forced a fumble on former teammate Ryan Fitzpatrick which was recovered by teammate Sean Chandler during the 36–20 win.
On March 16, 2020, the Giants placed the franchise tag on Williams. He signed the one-year tender on April 22, 2020. He was placed on the active/non-football injury list at the start of training camp on August 2, 2020. He was activated on August 14, 2020.
Leonard Williams (American football)