Democracy Is Strengthened by Casting Light On Spending in Elections Act of 2021 or the DISCLOSE Act of 2021 This bill addresses campaign finance, including by expanding the prohibition on campaign spending by foreign nationals, requiring additional disclosures of campaign expenditures, and requiring additional disclosures regarding certain political advertisements. First, the bill prohibits foreign nationals from participating in the decision-making process regarding an election expenditure. Additionally, the bill expands existing foreign money prohibitions to include disbursements for paid web-based or digital communications and federal judicial nomination communications. It also prohibits foreign nationals from contributing to campaigns related to ballot initiatives and referenda. The Federal Election Commission (FEC) must conduct an audit after each federal election cycle to determine the incidence of illicit foreign money. Next, the bill makes it unlawful to establish or use a corporation, company, or other entity with the intent to conceal an election contribution or donation by a foreign national. A violator is subject to criminal penalties—a fine, a prison term of up to five years, or both. Covered organizations (e.g., corporations, labor organizations, and political organizations) must, within 24 hours, file reports with the FEC to disclose campaign expenditures of more than $10,000 during an election cycle. Finally, the bill requires organizations to provide additional disclosures regarding political advertisements, including the donors who contributed the most money to that organization in the last year.