Alun Craig Williams is a British politician who has served as Parliamentary Private Secretary to the Prime Minister since October 2022. A member of the Conservative Party, he was the Member of Parliament (MP) for Cardiff North from 2015 to 2017, when he was defeated for reelection by Labour's Anna McMorrin. At the 2019 general election, Williams was elected as the MP for Montgomeryshire.

The Parliamentary Private Secretary to the Prime Minister is a Parliamentary Private Secretary serving the Prime Minister of the United Kingdom. The holder of the office is widely viewed as the Prime Minister's "eyes and ears" on the backbenches, serving as a liaison to the Prime Minister's parliamentary party. The Parliamentary Private Secretary is also responsible for meeting with members of Parliament when the Prime Minister is unavailable, and accompanying the Prime Minister to, and assisting them with preparations for Prime Minister's Questions. They usually sit directly behind the Prime Minister during question time.