• Hectare (ha), SI (metric system) unit of surface area

• The ISO 639 alpha-2 language code for the widely-spoken African Hausa language

• An onomatopoeia for laughter.

• The Highways Agency, an executive agency, part of the Department for Transport in the United Kingdom

• The Ha! comedy channel, one of the precursors to Comedy Central

• The British Rail pre-TOPS classification for twenty-four electric locomotives, later known as British Rail Class 71

• Haiti (FIPS 10-4 country code)

• Hawaiian Airlines (IATA airline designator)

• Hearst-Argyle, a media company in the United States

• Hells Angels, a motorcycle gang

• hemagglutinin or hemagglutination assay, in virology

• Heritage Auction Galleries, a prominent auction house, also known as Heritage Auctions.

• High availability

• Home agent, a computer router

• Home automation

• Homeowners association

• Hong Kong Housing Authority

• Hospital Authority, responsible for all public hospitals and institutes in Hong Kong

• Hospital Apprentice, a rank of the U.S. Navy

• Housing association

• HA postcode area, in Britain

• Hyaluronan, a molecule found in the body

• Hydroxylapatite, a mineral

• Head Automatica, an American powerpop band

• HA (video format)

• Headache (medical)

• Ha (ethnic group), a people in Tanzania

• Hāʼ, a letter of Arabic alphabet (ﻩ)

• Kha, a letter of Cyrillic alphabet

• Ha (kana), romanisation of the Japanese kana は and ハ

• Ha, Bhutan

• Ha Gorge in Crete, Greece

• Ha (mythology), a minor deity in Egyptian mythology

• the former symbol for the element dubnium (first called hahnium)

• Hå, a municipality in Norway

• "Ha" (song), a single by Juvenile

• Ha (album), an album by Talvin Singh

• Ha-, Hebrew prefix the

• Hectoampere, an SI unit of electric current (equal to 100 A)

See also

• Haha, disambiguation