25 December

Western Front

 * Poland: Germans driven back beyond the Bzura.
 * Galicia: Austrians defeated at Tarnow; the Austro-German offensive at an end.

Southern Front

 * Italy: Valona in Albania occupied.

Asiatic and Egyptian Theatres

 * Armenia: Battle of Sarikamish: Turkish counter invasion against the Caucasus reaches its limit.

Naval and Overseas Operations

 * German warships off Cuxhaven bombed by British naval airmen supported by HMS Arethusa and HMS Undaunted.