Аннотация:Theory of differential operators on associative algebras is not extended to the non-associative ones in a straightforward way. We consider differential operators on Lie algebras. A key point is that multiplication in a Lie algebra is its derivation. Higher order differential operators on a Lie algebra are defined as composition of the first order ones. The Chevalley--Eilenberg differential calculus over a Lie algebra is defined. Examples of finite-dimensional Lie algebras, Poisson algebras, algebras of vector fields, and algebras of canonical commutation relations are considered. Differential operators on graded Lie algebras are defined just as on the Lie ones.