Téwodros II (Ge'ez:ቴዎድሮስ, baptized as Sahle Dingil, and often referred to in English by the equivalent Theodore II) (c. 1818 – April 13, 1868) was the Emperor of Ethiopia from 1855 until his death.

He was born Kassa Haile Giorgis, but was more regularly referred to as Kassa Hailu (Ge'ez:ካሳ ኃይሉ — meaning "restitution" and "His [or the] power"). His rule is often placed as the beginning of modern Ethiopia, ending the decentralized Zemene Mesafint (Era of the Princes).