Celjski; German: Friedrich II Graf von Cilli) (17 January 1379 – 13 or 20 June 1454) was a Count of Celje and Ban of Croatia, Slavonia and Dalmatia.

Frederick was the son of Hermann II, Count of Celje and his wife Anna of Schaunberg.

Frederick II married Elizabeth of Frankopan and after her death in 1422, Veronika of Desenice.

He caused a stir when, in 1422, he allegedly murdered his first wife, Elisabeth of Frangepán, so that he could marry his lover, Veronika Dešnić.

His father also disowned him from his inheritance, but when his younger brother Hermann died suddenly in 1426, Frederick once again became the heir to the Cillei estate.