On September 12, 2019, President Trump announced his intent to nominate Lydon to serve as a United States District Judge for the United States District Court for the District of South Carolina. On October 15, 2019, her nomination was sent to the Senate. President Trump nominated Lydon to the seat vacated by Judge A. Marvin Quattlebaum Jr., who was elevated to the United States Court of Appeals for the Fourth Circuit on September 4, 2018. On October 16, 2019, a hearing on her nomination was held before the Senate Judiciary Committee. On November 7, 2019, her nomination was reported out of committee by a vote of 18–4. On December 4, 2019, the United States Senate invoked cloture on her nomination by a vote of 79–14. On December 5, 2019, her nomination was confirmed by a vote of 76–13. She received her judicial commission on December 10, 2019.

On April 10, 2018, President Trump announced his intent to nominate Lydon to serve as a United States Attorney of South Carolina. On April 12, 2018, her nomination was sent to the Senate. On May 10, 2018, her nomination was reported out of committee by a voice vote. On May 22, 2018, the Senate confirmed her nomination by voice vote. She was sworn into office on May 24, 2018. She left office on December 10, 2019, after being commissioned as a federal judge.

Cheryl “Sherri” A. Lydon (born February 21, 1962) is a United States District Judge of the United States District Court for the District of South Carolina. She previously served as the United States Attorney for the same district. She was the first woman appointed by a president to serve as U.S. Attorney for South Carolina.