The group, K&L Gates, will work with TikTok's internal U.S. management team, the company said. The group includes former congressmen Bart Gordon and Jeff Denham.
TikTok said the move will increase transparency around content moderation policies and its practices to protect users.
Created by Bytedance, TikTok allows users to create and share short videos with special effects, and is hugely popular in Southeast Asia, including India.
But similar to other social media companies like Facebook and Twitter, the video app too has faced the ire of regulators related to content moderation on its platform.
Facebook, the world's largest social network, is in the process of setting up an external oversight board to function as an independent court of appeals on content decisions from its moderators.