In cryptography, MUGI is a pseudorandom number generator (PRNG) designed for use as a stream cipher. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003, however, has been dropped to "candidate" by CRYPTREC revision in 2013.

Mugi may refer to:

• Mugi, Jayawijaya, Indonesia
• Mugi, Gifu, a former town in Gifu Prefecture, Japan
• Mugi District, Gifu, a former district in Gifu Prefecture, Japan
• Mugi, Tokushima, Japan
• Mugi Line, a railway line in southeastern Tokushima Prefecture, Japan
• Mugi, Ethiopia, the major town of Anfillo
• MUGI, a pseudorandom number generator