IntelliJ does not appear to support LSP natively but there is a community library called lsp4intellij which can be used in an IntelliJ plugin to provide language support.

We should also keep an eye on JetBrains Fleet, which will combine the functionality of all the other JetBrains IDEs and support LSP natively.

See also: https://github.com/gtache/intellij-lsp