The KiHa 181 series (キハ181系, Hyaku-hachijūichi-kei) was a diesel multiple unit (DMU) train type operated in Japan on limited express services between 1968 and 2010.

The KiHa 181 series was developed for use on limited express services on non-electrified mountainous routes, and was used on services such as the Tsubasa, Shinano, Yakumo, and Hamakaze on the main island of Honshu, and the Shiokaze and Nanpū in Shikoku.

[1] The KiHa 181 series trains were gradually displaced by the arrival of modern tilting diesel trains and increased electrification, and the last JR Shikoku cars were withdrawn by 1993.

The last JR-West cars remained in use on Hamakaze services until November 2010 when they were replaced by new KiHa 189 series DMUs, and were finally withdrawn in December 2010.

[1] A number of former JR-West KiHa 181 series cars were shipped to Myanmar after they were withdrawn, entering service from January 2013.