The Battle of ng ng (23 February 1885) was an important French victory during the Sino-French War. It is named after the town of ng ng, then in northern Tonkin, close to the border between China and Vietnam.

The Sino-French War (traditional Chinese: 中法戰爭; simplified Chinese: 中法战争; pinyin: Zhōngfǎ Zhànzhēng, French: Guerre franco-chinoise, Vietnamese: Chiến tranh Pháp-Thanh), also known as the Tonkin War and Tonquin War, was a limited conflict fought from August 1884 to April 1885. There was no declaration of war. Militarily it was a stalemate. The Chinese armies performed better than its other nineteenth-century wars, and the war ended with French retreat on land. However, one consequence was that France supplanted China's control of Tonkin (northern Vietnam). The war strengthened the dominance of Empress Dowager Cixi over the Chinese government, but brought down the government of Prime Minister Jules Ferry in Paris. Both sides ratified the Treaty of Tientsin. According to Lloyd Eastman, "neither nation reaped diplomatic gains."