Natshinnaung (Burmese: နတ်သျှင်နောင်, [naʔ ʃɪ̀ɴ nàʊɴ]; 1579–1613) was a Toungoo prince who was a noted poet and an accomplished musician, as well as an able military commander. He later became a rebellious ruler of Toungoo, and went over to ally himself with Portuguese at Thanlyin (Syriam). He was executed in 1613.

A grandson of King Bayinnaung and the eldest son of Minye Thihathu, Viceroy of Toungoo, the prince participated in King Nanda's campaigns to reconquer Siam in the early 1590s, and took part in the sacking of Nanda's capital Pegu in 1599. Natshinnaung became Crown Prince of Toungoo when his father proclaimed himself the king of Toungoo. In November 1600, he killed the captive king Nanda without his father's permission. On 21 March [O.S. 11 March] 1603, he married his lifelong love, Princess Yaza Datu Kalaya, for whom his famous poems were written. The marriage was cut short however as the princess died only seven months later.

When Natshinnaung succeeded as king following the death of his father on 11 August 1609, much of the country had been reunited under the leadership of King Anaukpetlun, one of Natshinnaung's cousins. In 1610, Anaukpetlun attacked Toungoo. The city surrendered on 4 September 1610 (2nd waning of Tawthalin 972 ME). Although the king re-appointed him as viceroy of Toungoo, Natshinnaung was deeply dissatisfied with his reduced status. Natshinnaung secretly made an alliance with Portuguese mercenary Filipe de Brito e Nicote, the ruler of Thanlyin, and invited de Brito to attack Toungoo. When de Brito's attack failed, Natshinnaung accompanied his "blood brother" de Brito back to Thanlyin.

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