National Commission on Online Platforms and Homeland Security Act This bill establishes the National Commission on Online Platforms and Homeland Security to address content on online and social media platforms that implicates national security concerns. Specifically, the commission shall identify, examine, and report on the ways online platforms have been used in furtherance or support of targeted violence or covert foreign state influence campaigns and how addressing such uses impacts users' free speech, privacy, civil rights, and civil liberties. Consistent with these purposes, the commission must analyze (1) online platforms' responses to such usage; (2) the impacts of algorithms and automated decision-making systems; and (3) the extent to which online platforms have transparent, consistent, and equitable policies and procedures to address violations of platform rules. The commission must then develop recommendations for how online platforms could address improper use through methods that are transparent and accountable while continuing to promote free speech and innovation on the internet and preserving individual privacy and civil rights. Additionally, the Department of Homeland Security must (1) research whether any connection exists between the use of online platforms and targeted violence; and (2) develop voluntary approaches that could be adopted by online platforms to address any correlations found while still preserving the individual privacy, civil rights, and civil liberties of users.