Litmus may refer to:

• Litmus test (chemistry), a common pH test
• Litmus test (politics), a question asked of a potential candidate
• Litmus (Mozilla), a test case management tool developed by Mozilla Co.
• Litmus (Battlestar Galactica), an episode in the first season of the Battlestar Galactica television series

Лакмус | Lackmustest | Lakmoes | Lakmus | Lakmusov papir | lackmuspapper | 石蕊试纸