Solid state, or solid matter, is one of the four fundamental states of matter.

Solid state may also refer to:

Electronics

Solid-state electronics, using semiconductors

Solid state ionics

Solid-state drive, a data storage device

Music

Solid State Records, a Christian music label

Solid State Records (jazz label), active in the 1960s

Solid State, a musical trio with DJ Dextrous

Solid State (Leon Russell album), 1984

Solid State (Jonathan Coulton album), 2017

Solid State, an album by Sam Phillips

Science

Solid-state chemistry, the chemistry of solids

Solid-state physics, the study of how atomic-scale properties lead to large-scale properties