Delta

Delta commonly refers to:
 * Delta (letter), Δ or δ in the Greek alphabet, also used as a mathematical symbol
 * River delta, a landform at the mouth of a river
 * Delta Air Lines, a major U.S. airline
 * Delta Connection
 * Delta Express
 * Delta Shuttle

Delta may also refer to:

Argentina

 * Paraná Delta

Canada

 * Delta, British Columbia
 * Delta (provincial electoral district)
 * Delta (electoral district)
 * Delta, Ontario, a village within the township of Rideau Lakes, Ontario

Egypt

 * Nile Delta

Nigeria

 * Delta State
 * Niger Delta

People's Republic of China

 * Pearl River Delta
 * Yangtze River Delta

United States

 * Delta, Alabama
 * Delta, Colorado
 * Delta, Illinois
 * Delta, Iowa
 * Delta, Louisiana
 * Delta, Missouri
 * Delta, Ohio
 * Delta, Pennsylvania
 * Delta, Utah
 * Delta, Wisconsin, a town
 * Delta (community), Wisconsin, an unincorporated community

Education

 * DELTA (ELT), a professional qualification in English language teaching
 * Delta, a quadra group used in socionics

Entertainment

 * Alt-J (∆), British indie band
 * Delta (album), a 2007 album by Delta Goodrem
 * Delta (Visions of Atlantis album), a 2011 album by symphonic metal band Visions of Atlantis
 * "Delta", a song by Crosby, Stills & Nash from Daylight Again
 * Delta (DVD)
 * Delta (TV series), a 1992 TV series starring Delta Burke
 * Delta (video game), a 1987 computer game
 * Delta FM or Delta Radio, a former UK radio station
 * Delta Machine, thirteenth studio album from Depeche Mode.

Fiction

 * Delta, a codename used by Jason Bourne in The Bourne Identity
 * E-103 Delta, a robot character in Sonic the Hedgehog
 * Delta Megazord, a zord in Power Rangers in Space
 * Deltas, the working class of Aldous Huxley's Brave New World
 * Delta AI, a supporting character in Red vs. Blue
 * Subject Delta, the protagonist of Bioshock 2
 * Delta Squad, the main characters in Gears of War

Companies
Along with the aforementioned Delta Air Lines, other companies named Delta include:
 * Delta (pen manufacturer), a manufacturer of fine writing instruments
 * Delta Cafés, a Portuguese coffee roasting and coffee packaging company
 * Delta Electric Company, defunct electrical parts company
 * Delta Electricity, an Australian power generation company
 * Delta Electronics, a power supplies and brushless fans manufacturer
 * Delta Faucet Company, a plumbing fixtures company
 * Delta Galil Industries, an Israeli textile company
 * Delta Holding, a Serbian import-export, banking, insurance and retail corporation
 * Delta Hotels, a Canadian hotel chain
 * Delta Machinery, a stationary power tools and equipment company
 * Delta Motor Corporation, a South African car manufacturer owned by General Motors
 * Visa Delta or Visa Debit

Organizations

 * Delta Dental, an American dental plan system
 * Delta Force, a U.S. Army special operations force
 * Delta Sigma Theta, an incorporated Howard University public service sorority founded in 1913.
 * Delta Works, a flood-protection works in the Netherlands
 * Emergency Response Unit (Norway), a Norwegian special police forces team

Computer science

 * Delta (computer), a Russian ZX Spectrum clone
 * Delta encoding, a technique in computer communications and version-control

Earth sciences

 * Delta switching, the process by which some rivers change their course near their deltas
 * Tropical Storm Delta (2005), a tropical storm of the 2005 Atlantic hurricane season
 * Δ, or epicentral distance

Mathematics

 * (ε, δ)-definition of limit
 * Delta (finance), a first order derivative of an option pricing formula versus the underlying spot price
 * Delta method, a method for approximating the distribution of a function of a random variable
 * Δ, or difference operator
 * Δ, or modular discriminant
 * Δ, or symmetric difference
 * Δ, a change of state between two before and after state schemas in the Z notation
 * $$\Delta^0_n,$$ a classification in the arithmetical hierarchy
 * $$\Delta^1_n,$$ a classification in the analytical hierarchy
 * $$\Delta^P_i,$$ a classification in the polynomial hierarchy
 * $$\nabla$$ (the nabla symbol), an inverted delta representing del, a vector differential operator
 * Delta connective, a unary connective in t-norm fuzzy logics
 * $$ \delta_{ij}$$, the Kronecker delta function
 * $$ \delta(x-y) $$, the Dirac delta function

Medicine and biology

 * Delta (genus), Old World genus of potter wasps
 * Delta (ligand), an activator of the Notch signaling pathway
 * DELTA (taxonomy), a data format used in taxonomy for recording descriptions of living things
 * Delta wave, the frequency band of brain activity between 1 and 4 hertz
 * Delta wave, on an ECG, the slurred upstroke of the QRS complex which is characteristic of Wolff–Parkinson–White syndrome

Physics

 * Delta baryon, a subatomic particle with spin 3/2
 * High-leg delta, three phase electrical circuit

Vehicles

 * Delta (rocket family), a family of launch vehicles
 * Delta class submarine, a Soviet/Russian SSBN submarine series (NATO reporting name)
 * Delta Formation, an aircraft formation flying manoeuvre in the shape of a V
 * Delta wing, an aircraft wing planform in the form of a triangle
 * Oldsmobile Delta 88, a full-size General Motors car made from 1965 to 1983
 * GM Delta platform, a compact car automobile platform from General Motors
 * Lancia Delta, an Italian rally car
 * DeltaWing, a prototype of racing car
 * Delta, a tricycle layout

Industry

 * Delta robot, a specialized type of parallel robot

Other uses

 * Delta blues, one of the earliest styles of blues music
 * Ilford Delta, a photographic film
 * Delta, the refractory section in the roof of an electric arc furnace
 * Delta, a font designed by Aldo Novarese

People with the name

 * Penelope Delta (1874–1941), Greek author
 * Delta Burke (born 1956), American actress
 * Delta Goodrem (born 1984), Australian singer
 * Delta (wrestler) (born 1985), Mexican professional wrestler