In mathematics, Steinberg group means either of two distinct, though related, constructions of the mathematician Robert Steinberg:
- Steinberg group (K-theory) St(A) in algebraic K-theory.
- Steinberg group (Lie theory) is a 'twisted' group of Lie type, in particular one of the groups of type <sup>3</sup>D<sub>4</sub> or <sup>2</sup>E<sub>6</sub>.