HOM, HoM or HOm can refer to:

• Hall of mirrors effect, in 3D computer graphics
• Hands On Miami, a volunteer community-service organization in Miami, Florida
• Heart of Misery, a song by Finnish rock band The Rasmus
• Holland (Amtrak station), a railway station in Michigan, USA (Amtrak station code HOM)
• HOm scale, a particular model railway scale or gauge
• Homer Airport in Homer, Alaska (IATA code HOM)
• House of Milan, American publisher of bondage magazines
• Armenian Relief Society, alternate acronym HOM, based on the Armenian name Հայ Օգնութիան Միութիւն
• head(s) of mission, for diplomatic/consular missions

Hom may refer to:

• Hom (musical instrument), a class of trumpet-like wind instruments, as used in pre-Columbian and traditional Maya music of Mesoamerica
• Hom functor, as defined in the mathematical field of category theory, a functor or specialised type of morphism between small category sets
• HOm scale, a particular model railway scale or gauge
• Hom, a mountain in northwestern Slovenia
• HOM, a “higher-order modulation”, to be used in HSPA+ mobile networks
• HOM (Underwear brand), a French underwear/lingerie brand

H0m scale or H0m gauge is used to represent metre gauge trains in the same scale as HO scale. It runs on gauge tracks (which is the same as TT scale). Modern HOm trains run on realistic-looking two-rail track, which is powered by direct current (varying the voltage applied to the rails to change the speed, and polarity to change direction), or by Digital Command Control (sending commands to a decoder in each locomotive). It is a popular scale in Europe, particularly for trains of Swiss outline.

House of M is an eight-issue comic book limited series and crossover storyline published by Marvel Comics in 2005. Written by Brian Michael Bendis and illustrated by Olivier Coipel, its first issue debuted in June 2005 as a follow-up to the events of the Planet X and Avengers Disassembled storylines, in which the mutant superhero Scarlet Witch suffered a mental breakdown and tried to alter the fabric of reality to recreate her lost children. Scarlet Witch's father, Magneto, and her twin brother, Quicksilver, played major roles in the series.