sphinxcontrib-plantuml is a plantuml extension for Sphinx. First, you may need to specify plantuml command in your conf.py: plantuml = ['java', '-jar', '/path/to/plantuml.jar'] Instead, you can install a wrapper script in your PATH: % cat /usr/local/bin/plantuml #!/bin/sh -e java -jar /path/to/plantuml.jar "$@" EOT % chmod +x /usr/local/bin/plantuml Then, write PlantUML text under .. uml:: directive: .. uml:: Alice - > Bob: Hi! Alice