The 2018 farm bill or Agriculture Improvement Act of 2018 is United States legislation that re-authorized many expenditures in the prior United States farm bill. The $867 billion reconciled farm bill was passed by the Senate on December 11, 2018, and by the House on December 12. On December 20, 2018, it received President Donald Trump's signature and became law.

The 2018 Farm Bill establishes a new federal hemp regulatory system under the US Department of Agriculture which aims to facilitate the commercial cultivation, processing, and marketing of hemp. The 2018 Farm Bill removes hemp and hemp seeds from the statutory definition of marijuana and the DEA schedule of Controlled Substances. It even makes hemp an eligible crop under the federal crop insurance program. The 2018 Farm Bill also allows the transfer of hemp and hemp-derived products across state lines provided the hemp was lawfully produced under a State or Indian Tribal plan or under a license issued under the USDA plan.

The introduction of the Farm Bill has created much speculation that the cannabis plant itself will be removed from Schedule 1 classification by the US government.