JF may refer to:
The junction gate field-effect transistor (JFET or JUGFET) is one of the simplest types of field-effect transistor.
Journaled File System or JFS is a 64-bit journaling file system created by IBM. There are versions for AIX, eComStation, OS/2, and Linux operating systems.
The JFK Express, advertised as The Train to The Plane, was a limited express service of the New York City Subway, connecting Midtown Manhattan to John F.
JFE Holdings, Inc. (JFE（ジェイエフイー）ホールディングス株式会社, Jeiefuī Hōrudingusu Kabushiki-gaisha) is a corporation headquartered in Tokyo, Japan.