Delta most commonly refers to:

• Delta (letter), the 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 also has the following meanings:

Abbreviations

• DELTA (ELT), an advanced diploma in English language teaching
• DELTA (taxonomy), the DEscription Language for TAxonomy

Canada

• Delta, British Columbia (the town located immediately south of the Fraser River delta)
• Delta (provincial electoral district)
• Delta (electoral district), a federal electoral district

Nigeria

• Delta State, Nigeria

United States

• Delta, Colorado
• Delta, California
• Delta, Iowa
• Delta, Kentucky
• Delta, Louisiana
• Delta, Missouri
• Delta, Ohio
• Delta, Pennsylvania
• Delta, Utah
• Delta, Wisconsin
• Delta Charter Township, Michigan
• Delta County, any of several

See also: Mississippi Delta (disambiguation)

Astronomy and physics

• Delta baryon, a subatomic particle with spin 3/2
• In Bayer designation, one of the stars in a constellation (e.g., Delta Cygni)
• Delta-v, a term used in astrodynamics for the total 'effort' to change from one space trajectory to another

Aeronautics

• Delta wing
• Delta rocket, a family of launch vehicles
• Delta Formation (Aircraft), a formation flying manoeuvre in the shape of a V

Earth sciences

• Delta switching, the process by which some rivers change their course near their deltas
• Tropical Storm Delta (2005)
• ” and delta are used to represent epicentral distance in seismology.

Mathematics and computer science

• Δ often denotes a difference; δ can represent a small change or amount
• In elementary set theory and Boolean algebras, Δ usually denotes the symmetric difference
• An inverted delta (\nabla), known as del or nabla, is used as a vector differential operator
• Kronecker delta, a function of two variables which is 1 when they are equal
• Dirac delta function, a distribution used as an approximation for a spike function
• Delta encoding, a technique in computer communications and version-control
• In formal fuzzy logic, Δ denotes a unary connective representing the full truth of a proposition (often called Baaz Delta connective)
• Δ indicates a change of state between two before and after state schemas in the Z notation

Mathematical finance

• One of the Greeks (finance) used in option and derivatives pricing representing the rate of change of the option price with respect to changes in the underlying price