SO

SO or so may refer to:

Arts and entertainment

"SO" (Sons of Anarchy), the third season premiere of the FX television series Sons of Anarchy
So Television, a British TV production company

.so, the top-level Internet domain of Somalia
.so, a filename extension for a shared object (a dynamic library or module) in Unix and Linux
Shift Out, an ASCII control character in computing
Small-outline integrated circuit
StackOverflow, a programming Q&A site
Sony's mobile phones in Japan

SO (complexity), second-order logic in descriptive complexity
Special orthogonal group, a subset of an orthogonal group
SO(2), a term used in mathematics, the group of rotations about a fixed point in the Euclidean plane
SO(3), a term used in mathematics, the group of rotations about a fixed point in three-dimensional Euclidean space
SO(4), a term used in mathematics, the group of rotations about a fixed point in four-dimensional Euclidean space
SO(5), a term used in mathematics, the special orthogonal group of degree 5 over the field R of real numbers
SO(8), a term used in mathematics, the special orthogonal group acting on eight-dimensional Euclidean space
$\mathfrak{so}(n)$ , the corresponding special orthogonal Lie algebra

Sulfur monoxide
SO(10) (physics), a term used in particle physics, one of the grand unified theories is based on the SO(10) Lie group

Sō, a Japanese surname and given name
Su (surname) ({{lang|zh|苏}}/{{lang|zh|蘇}}), a Chinese surname and a Korean surname ({{lang|ko|소}}) derived from it
So (Korean name) (蘇 or 邵)

So (סוֹא), King of Egypt, usually identified with Osorkon IV
So (dairy product), a type of dairy product made in ancient Japan
Sales order, an order received by a business from a customer
Sao civilisation or So, an African civilisation and population that flourished from ca. the 6th century to ca. 15th century
Shell on, a form of presentation in shrimp marketing
Strikeout, in baseball