Hannah Montana, a popular Disney Channel TV show

Haunted Mansion, a dark ride attraction in several Disney theme parks

Heavy metals, higher atomic weight metallic elements

Hospital Corpsman, in the United States Navy

HM (patient), pseudonym of a man with no long-term memory (also written H.M.)

H&M, or Hennes & Mauritz, a Swedish clothing company

Hindley-Milner, a type system

Heard Island and McDonald Islands: ISO 3166 digram and FIPS PUB 10-4 territory code

Fender HM Strat, a superstrat electric guitar

Air Seychelles: International Air Transport Association (IATA) code

The academic area of Hospitality management studies

Hindustan Motors, an automobile manufacturer of Indian origin

HM (magazine), a Christian Hard rock magazine

hectometre, an SI unit of length

His/Her Majesty, a form of address for a monarch and his/her consort