Java Platform, Micro Edition or Java ME (formerly referred to as Java 2 Platform, Micro Edition or J2ME), is a collection of Java APIs for the development of software for resource constrained devices such as PDAs, cell phones and other consumer appliances. Java ME is formally a specification, although the term is frequently used to also refer to the runtime implementations of the specification. Java ME was developed under the Java Community Process as JSR 68. The evolution of the platform has abandoned the umbrella Java Specification Request in favor of separate JSRs for the different flavors of Java ME.

Java ME was designed by Sun Microsystems and is a replacement for a similar technology, PersonalJava.

Java ME has become a popular option for creating games for cell phones, as they can be emulated on a PC during the development stage and easily uploaded to the phone. This contrasts with the difficulty of developing, testing, and loading games for other special gaming platforms such as those made by Nintendo, Sony, and others, as expensive system-specific hardware and kits are required.

Sun Microsystems has tended not to provide free binary implementations of its Java ME runtime environment for mobile devices, rather relying on third parties to provide their own, in stark contrast to the numerous binary implementations it provides for the full Java platform standard on server and workstation machines. One of the notable omissions is for Microsoft Windows Mobile (Pocket PC) based devices, despite an open letter campaign to Sun to release a rumoured complete project "Captain America" which is such an implementation.