LotusScript is a programming language used in Lotus Notes and other IBM Lotus products. It is very similar to Visual Basic (code can usually be copied between languages with little modification), but has many specific built-in classes for accessing objects within the Lotus Notes/Domino environment.

The Lotus Domino Designer application is the primary IDE used for developing programs in LotusScript, and also allows development in [Java]/[JavaScript] and Formula language.