MP4播放器（在中国常简称为MP4）是从中国大陆产生的常见可携式媒体播放器市场行销名词。与MP3播放器这类几乎广泛播放MPEG-1 Audio Layer 3音乐档的设备不同，MP4播放器跟MPEG-4 Part 14格式并没有直接关系。相反地，它被市场认定为是MP3播放器的“下一代”（3+1=4）。现在已有厂商发行MP4播放器的继承者──MP5播放器。MP4播放器仍是目前市场的大宗，而各个厂商也制造了各式各样的MP5播放器。但是MP5播放器并没有明确的定义，而一些中国厂商已经开始制造所谓的“MP6”甚至“MP7”。

The name MP4 player is a marketing term for inexpensive portable media players, usually from little known or generic device manufacturers. The name itself is a misnomer, since most MP4 players through 2007 were incompatible with the MPEG-4 Part 14 or the .mp4 container format. Instead, the term refers to their ability to play more file types than just MP3. In this sense, in some markets like Brazil, any new function added to a given media player is followed by an increase in the number, for example an MP5 or MP12 Player, despite there being no corresponding MPEG-5 standard (as of 2015, the current standard, still being developed, is MPEG-4).