Most of the following encyclopedias are freely available online, unless otherwise indicated.
V. 1-5: General subjects; 7 subsequent "Yidn" volumes with bibliographies and indexes. In Yiddish.
Some volumes online here.
Encyclopedia Judaica
Comprehensive general encyclopedia for Jewish topics. Available from home with your Library card and PIN.
1904 encyclopedia with strong Yiddish coverage.
Jewish Women: A Comprehensive Historical Encyclopedia.
International coverage of many Yiddish writers and actresses.
Includes American female Yiddish cultural figures. Full bibliographies. In print.
Jewish Women's Archive
Includes many Yiddish figures, such as actors and writers.
ייִדישע פֿאָלקס־־ ־ענציקלאָפּעדיע: פֿאַר ייִדישע רעליגיע, געשיכטע, פֿילאָזאָפֿיע...און אַנדערע ענינים
Yidishe folḳs-entsiḳlopedye : far Yidishe religye, geshikhṭe, filozofye... un andere inyonim.
Ed. Symcha Petrushka,. 1949. Jewish popular encyclopedia, in Yiddish.
Comprehensive encyclopedia.