CH
CH, Ch, cH, or ch may refer to:

Arts and entertainment
Television channel (sometimes abbreviated as "ch." for television and cable stations)
Chaos;Head, a video game
Clone Hero, a clone game version of popular rhythm game series Guitar Hero.
CollegeHumor, a comedy website
E!, a defunct Canadian television system that went by the name CH from 2001 to 2007

Businesses
Bemidji Airlines (IATA code CH)
Carolina Herrera, a fashion designer based in New York
Columbia Helicopters, an aircraft manufacturing and operator company based in Aurora, Oregon, United States

In language
Ch (digraph), considered a single letter in several Latin-alphabet languages
Chamorro language: ISO 639 alpha-2 language code (ch)

Science and technology
Chemistry
The methylidyne radical (a carbyne); CH• (or •CH), CH3• (or ⫶CH)
The methylidyne group ≡CH
The methine group (methanylylidene, methylylidene) =CH−

Mathematics and computing
Chomsky hierarchy, in computer science, a containment hierarchy of classes of formal grammars
Continuum hypothesis, in set theory
Hyperbolic cosine, in mathematics, a hyperbolic function, ch(x) = cosh(x)
Curry–Howard correspondence, the relationship between computer programs and mathematical proofs
CH register, the high byte of an X86 16-bit CX register
Ch (computer programming), a cross-platform C/C++ interpreter
Contraction hierarchies, in computer science, a speed-up technique for finding shortest paths in a graph

Medicine
Cluster headache
Cholesterol
Congenital hypothyroidism, a condition of thyroid hormone deficiency present at birth
Cerebellar hypoplasia, characterized by reduced cerebellar volumeCerebellar hypoplasia (non-human)French catheter scale, a scale for medical catheters, also abbreviated as Fr

Military technology
Cargo helicopter (U.S. military helicopter alpha-numeric prefix)
Chain Home, a World War II radar array
Heavy cruiser (U.S. Navy ship code CH, standing for "Cruiser, Heavy")

In other sciences
Clay of high plasticity (USCS soil type CH)
Cassini-Huygens

Places
Confoederatio Helvetica, the formal name for Switzerland, Latin in origin
ISO country code for Switzerland
.ch, the Internet country code top-level domain for Switzerland
CH postcode area; the Chester postcode area in the UK
Chihuahua (state), the State of Chihuahua, Mexico
Conservation Halton, in Ontario, Canada
China (FIPS and NATO country code CH)
Chandigarh, a union territory of India

Other uses
Chain (length), a unit of linear measure in the Imperial system
Championship (dog), a dog qualifying for a championship at a conformation show, prefixed "Ch."
Christ's Hospital, Horsham, West Sussex
Companion of Honour, a British and Commonwealth honour
Chaudhary, an honorific used in the Indian and Pakistani Punjab regions
Metres above the Sea (Switzerland), an elevation reference system
The logo for the Montreal Canadiens ice hockey team
Adobe Character Animator, an Adobe software