Captain David Rabin painted the Hebrew words Shalom ("peace") and L'chaim ("to life") on the exterior walls of the Starfleet mission to planet Obsidian, following the local custom of using tribal marks in this way. (TOS novel: Vulcan's Forge)
A Germanic language written using the Hebrew aleph-bet and containing many Hebrew words and concepts, Yiddish was commonly spoken by Jews of European ancestry, and numerous Yiddish words entered into the English language. Sergei and Helena Rozhenko were fluent in Yiddish. (TNG - Starfleet Academy novel: Worf's First Adventure)
- Real life Star Trek actors known to speak Yiddish are Whoopi Goldberg (Guinan), Saul Rubinek (Kivas Fajo), William Shatner (James T. Kirk) and Leonard Nimoy (Spock).