Harmo is an American harmonica brand based in Eagle, Idaho, founded in 2016 by professional harmonica player David Herzhaft. The company designs and quality-checks its instruments in the USA, positioning itself between mass-produced factory harmonicas and expensive hand-customized models. Herzhaft's background as a working player informs the brand's approach to tuning, tolerances, and out-of-the-box playability.

The product line centers on diatonic harmonicas, most notably the Harmo Polar, which is set up with an overblow-friendly configuration aimed at blues, folk, country, rock, and funk styles. Harmo also offers a Polar natural minor version tuned for minor blues pentatonic, natural minor, and dorian playing, alongside chromatic models and specialty tunings. The brand produces its own accessories as well, including harmonica cases, pouches, repair and maintenance tools, and lip balm formulated for players.

Beyond instruments, Harmo operates an online harmonica school with lessons, transcriptions, and instructional books authored by Herzhaft, giving the brand a dual identity as both a manufacturer and an educational resource within the harmonica community.

Harmo has 1 product cataloged on Equipboard, including Harmonicas.