The Treaty of Giyanti (also known as the Treaty of Gianti Java, the Gianti Agreement, or the Giyanti Treaty) was signed and ratified on February 13, 1755 in Giyanti (southeast of Karanganyar, Central Java) between Prince Mangkubumi, the Dutch East India Company, and Sunan Pakubuwono III along with his allies. Based on the terms of the agreement, the eastern half of the Sultanate of Mataram in central Java was given to Pakubuwono III with Surakarta as its capital, while the western half was given to Prince Mangkubumi with its capital in Yogyakarta. This treaty marked the division of former territory of Mataram Sultanate between Surakarta Sunanate and Yogyakarta Sultanate.

After the signing of the treaty, Prince Mangkubumi changed his title as prince and became known as Sultan Hamengkubuwono I. The accord did not end hostilities in the area since Prince Sambernyawa (or Raden Mas Said) continued to fight against Pakubuwono III. The background of this treaty is perpetuated in a babad entitled Babad Giyanti.