Nagaoka Co., Ltd. is a Japanese audio manufacturer based in Higashine, Yamagata Prefecture, founded in 1940. The company began in precision watchmaking before transitioning to phonograph styli and cartridges, and has since become one of the most established specialists in analog playback. Nagaoka produces its cartridges entirely in-house, manufacturing each component — including the diamond tips — at its own factory, a rarity among cartridge makers.

The brand is best known for its Moving Permalloy (MP) series of moving-magnet-style phono cartridges, which share a common body and swappable stylus design. The range spans from the entry-level MP-110 through mid-tier models like the MP-150, MP-200 and MP-300, up to the flagship MP-500 with its boron cantilever and line-contact diamond. Nagaoka also produces dedicated mono cartridges, the more affordable JT series, and a line of record-care accessories including cleaning cloths, sleeves, and stylus cleaners.

Nagaoka cartridges have a reputation among turntable users for a warm, full-bodied tonal character that pairs well with a wide range of tonearms using the standard half-inch mount. The MP-110 in particular is frequently recommended as a step-up cartridge for mid-range turntables, while higher models in the series are favored by vinyl enthusiasts looking for a detailed but non-clinical presentation.

Nagaoka has 1 product cataloged on Equipboard, including DJ Accessories.