The Battle of the Alma (short for Battle of the Alma River) was a battle in the Crimean War between an allied expeditionary force (made up of French, British, and Egyptian forces) and Russian forces defending the Crimean Peninsula on 20 September 1854. The allies had made a surprise landing in Crimea on 14 September. The allied commanders, Maréchal Jacques Leroy de Saint-Arnaud and Lord Raglan, then marched toward the strategically important port city of Sevastopol, 45 km (28 mi) away. Russian commander Prince Alexander Sergeyevich Menshikov rushed his available forces to the last natural defensive position before the city, the Alma Heights, south of the Alma River.

The allies made a series of disjointed attacks. The French turned the Russian left flank with an attack up cliffs that the Russians had considered unscalable. The British initially waited to see the outcome of the French attack, then twice unsuccessfully assaulted the Russians' main position on their right. Eventually, superior British rifle fire forced the Russians to retreat. With both flanks turned, the Russian position collapsed and they fled. The lack of cavalry meant that little pursuit occurred.

The battle cost the French roughly 1,600 casualties, the British 2,000, the Ottomans 503, and the Russians some 5,000.