Flat fee MLS (sometimes referred to as "flat rate mls" or "fixed fee mls") refers to the practice in the real estate industry of placing pertinent information about a property for sale into the database of the local Multiple Listing Service (MLS) for a set fee or dollar amount as opposed to a commission based on the sales price of the property.

In this instance, the Listing contract between the real estate broker and the property owner typically requires the broker to enter the property into the MLS and calls for the seller to pay the broker a flat fee for the service. The net effect is to make the real estate industry's standard MLS available as a marketing tool to house sellers without the necessity of the seller purchasing a package of other services from the real estate agent.