The Division of Market Regulation is a department within the United States Securities and Exchange Commission (SEC) which regulates major securities market participants, including: broker-dealer firms, self-regulatory organizations (SROs), which include the stock exchanges and the National Association of Securities Dealers (NASD), Municipal Securities Rulemaking Board (MSRB), clearing agencies (SROs that help facilitate trade settlement), and transfer agents (parties that maintain records of stock and bond owners).

The primary responsibilities of the Division of Market Regulation include monitoring the market, reviewing new rules or rule amendments proposed by SROs, mediating disputes within market operations, and carrying out the SEC's financial integrity program for broker-dealers.