《1933年证券法》（Securities Act of 1933）是美国在1929年的华尔街股市风暴及随后的大萧条背景下所通过的法案。

The United States Congress enacted the Securities Act of 1933 (the 1933 Act, the Securities Act, the Truth in Securities Act, the Federal Securities Act, or the '33 Act, Title I of Pub. L. 73-22, 48 Stat. 74, enacted May 27, 1933, codified at 15 U.S.C. § 77a et seq.), in the aftermath of the stock market crash of 1929 and during the ensuing Great Depression. Legislated pursuant to the interstate commerce clause of the Constitution, it requires that any offer or sale of securities using the means and instrumentalities of interstate commerce be registered with the SEC pursuant to the 1933 Act, unless an exemption from registration exists under the law. "Means and instrumentalities of interstate commerce" is extremely broad, and it is virtually impossible to avoid the operation of this statute by attempting to offer or sell a security without using an "instrumentality" of interstate commerce. Any use of a telephone, for example, or the mails, would probably be enough to subject the transaction to the statute.