Saw Binnya (died 1541) is viceroy of Martaban (Mottama) from c. 1510s to 1539, and the self-proclaimed king of the rump Hanthawaddy Kingdom from 1539 to 1541.

First appointed viceroy of Martaban, one of the three provinces of the Mon-speaking kingdom, by King Binnya Ran II, Saw Binnya rules the province like a sovereign during the reign of King Takayutpi, his brother-in-law.

Under his leadership, the port of Martaban becomes an international entrepôt, and grows tremendously wealthy.

He is able to build up a formidable military of his own, replete with Portuguese mercenaries and arms, but his refusal to contribute to Takayutpi's war effort against the Toungoo Dynasty greatly facilitates Toungoo's conquest of Pegu in 1538–1539, and ultimately results in the downfall of his own fiefdom in 1541.

He is subsequently executed.