30 October

Western Front

 * Battle of the Yser: Germans forced by floods to retreat.
 * Ypres closely pressed by the Germans.
 * Germans press back French along the Aisne.

Eastern Front

 * Poland: Russians defeat Germans at Bakalaryevo.

Naval and Overseas Operations

 * South Africa: Rebels routed at Schuit Drift.
 * SMS Königsberg discovered hiding in Rufiji River (East Africa).

Political

 * Great Britain: Trial of the German spy Karl Hans Lody begins.
 * Turkey: Allies' Ambassadors ask for passports.